physics - question for me
Vectors examples
- velocity - momentum - force - electromagnetic fields - weight
sclars example
- volume - density - speed - energy - mass - time - work
which of the following is dimensionless: 1. electron volt 2. lux 3. mole 4. hertz 5. no answer is correct
3. mole
Harmonic oscillation
T = 1 / f
particle wavelength given by the de Broglie relation is: a quotient of the Planck constant and momentum of the particle b. a quotient of the momentum and mass of the particle c. a quotient of the plank constant and mass of the particle d. a quotient of the mass and momentum of the particle
a quotient of the Planck constant and momentum of the particle λ = h/mv, where λ is wavelength, h is Planck's constant, m is the mass of a particle, moving at a velocity v. de Broglie suggested that particles can exhibit properties of waves
which of the following phenomena has nothing to do with interference of light? a. "mirroring" of air above the hot surface of a road b. dark stripes or lines which can be seen in poorly adhering glass tables. c. the colored pattern which can be seen on water surface polluted by a small amount of diesel oil
a. "mirroring" of air above the hot surface of a road
find the amount of substance which contains more molecules than 1kg of liquid water at normal pressure and temp of 0c. a. 1 kg of ethane b. 1 kg of O2 c. 1 kg of glucose d. 1 kg of mercury
a. 1 kg of ethane
In which of the following are there more molecules than in 1kg of water? a. 1 kg of helium b. 1 kg of oxygen c. 1 kg of glucose d. 1 kg of air
a. 1 kg of helium
which of the atmospheric pressure is commonly measure in Prague or Brno? a. 100 kPa b. 1000 pa c. 1m mercury column
a. 100 kPa
bubble air pressure values represents the average atmospheric pressure at the sea level? a. 101 kPa b. 120 torr
a. 101 kPa
which of the following amount of substances involves fewer molecules Tham is the number of molecules present in 1g of water: a. 1g of glucose b. 1g of helium c. 1 mole of hydrogen
a. 1g of glucose
water flows from through a pipe. if the ratio of radii of a narrower and a wider section of the pipe is 1:3, than the ratio of water flow-rates in these two sections is: a. 9:1 b. 3:1 c. 2:1
a. 9:1 (in square)
A capillary tube put in a liquid leads to a capillary depression. If a capillary of smaller cross sectional area is used there is: a. An increased fall of liquid level in the capillary b. A lowered fall of liquid level in the capillary c. No change in the fall of the liquid level in the capillary d. Often a change from depression to elevation
a. An increased fall of liquid level in the capillary
The force on a current carrying electrical conductor in a magnetic field would be zero if the: a. Angle between the conductor and the vector B is 0o b. The current is alternating c. Angle between the conductor and the vector B is 90o d. The lines of force of the magnetic field are parallel
a. Angle between the conductor and the vector B is 0o
the physical principle for a spray gun (an airbrush) is the: a. Bernoulli's equation b. continuity equation c. pascal's principle
a. Bernoulli's equation
The surface tension of liquids can be defined as the: a. Force perpendicular to unit length of edge of surface membrane of liquid b. Intensity of electrical tension between a liquid and its surroundings c. Force needed to tear the surface of a liquidd) Force produced per unit surface area of liquid
a. Force perpendicular to unit length of edge of surface membrane of liquid
the term pv in the equation of state of an ideal gas has units? a. J b. JK c. JK^-1 d. JK^-1 x mol^-1
a. J
find the right form of the law of radioactive decay: a. N = N0 e−λt b. I = I0 eλt c. N0 = N e-λt d. N = Nt eλt
a. N = N0 e−λt
If we connect the inside of two different size soap bubbles using a hollow pipe surface tension theory predicts that the: a. Smaller one will disappear and the bigger will grow b. Volume of the bubbles will become equal c. We will not see any change in sizes of bubbles d. Is not possible to predict the behavior of the bubbles
a. Smaller one will disappear and the bigger will grow
If the plates of a capacitor are moved closer together to half the original distance. The capacitance: a. Will increase twice b. Will decrease to half c. Will increase by the original value d. Will stay constant
a. Will increase twice
. Which formula can be used to calculate of impedance of a capacitor? a. Xc = 1/ωC b. Xc = ω/C c. Xc = ωC d. Xc = U/Q
a. Xc = 1/ωC
sea water changed to ice at -3 Celsius. this phenomenon was caused by: a. a presence of dissolved salt b. increase evaporation c. increase ambient pressure d. the presence of air bubbles
a. a presence of dissolved salt
A thermocouple is: a. a source of electric voltage b. a device utilizing the heat produced by electric current.
a. a source of electric voltage
which one is a vector? a. acceleration b. pressure c. electric voltage d. energy
a. acceleration
two parallels wires with electric currents of the same direction: a. are attracted b. are repulsed c. repulse only when switching on the current
a. are attracted Two parallel wires carrying current in the same direction attract each other while two beams
the state of 'weightlessness' is always present: a. at a free fall in vacuum if there is a vacuum around the tent chamber
a. at a free fall in vacuum
a body doing simple harmonic oscillations has the 'MAXIMUM' POTENTIAL ENERGY' in the moment when: a. at maximum displacement b. at zero displacement c. when the potential energy of the oscillator is constant
a. at maximum displacement
a simple harmonic oscillation reaches MINIMUM KINETIC ENERGY: a. at maximum, displacement b. at zero displacement c. kinetic energy of this oscillator is constant
a. at maximum, displacement
in the phenomenon of capillary depression, narrowing of the capillary causes: a. bigger depression of the liquid surface in capillary b. smaller depression of the liquid surface in capillary c. no change of the liquid surface position
a. bigger depression of the liquid surface in capillary
in the phenomenon of capillary elevation, narrowing of the capillary causes: a. bigger elevation of the liquid surface in the capillary a. smaller elevation of the liquid surface in the capillary c. no change of the liquid surface
a. bigger elevation of the liquid surface in the capillary
at the present time, the lowest achievable temperature is: a. boiling point of helium b. less than 0.1 k c. about -280 k d. -273.15 k
a. boiling point of helium
the Carnot cycle is formed: a. by two isothermal and two adiabatic processes b. by one isothermal and two adiabatic processes c. by two isothermal two isobaric processes
a. by two isothermal and two adiabatic processes
Bernoulli's equation is special case of law of: a. conversation of energy b. conversation of mass c. Pascal's law
a. conversation of energy
which sets contain only solar quantities: a. distance, surface tension, pressure b. energy, intensity of electric field c. momentum, energy, moment of force
a. distance, surface tension, pressure
which of the following can easily trajectory when it passes through an electric field? a. electron, proton, alpha-particle b. proton, electron, photon c. electron, photon, meson
a. electron, proton, alpha-particle
which of the particle is NOT deflected from its original trajectory by a magnetic field? a. hydrogen atom b. B+ particle c. proton d. alfa paticle
a. hydrogen atom
the photoelectric phenomenon (effect) takes place in the situation of: a. impact of photons of high energy onto atoms of solids b. impact of electrons onto a semiconductor c. absorption of visible light by atom nucleus d. emission if x-rays from anode of the X-ray tube
a. impact of photons of high energy onto atoms of solids
Gamma rays originate mainly: a. in an atomic nucleus b. by the acceleration of electrically charged particles c. by the impacts of electron on the cathode of an X-ray tube.
a. in an atomic nucleus
how should three 3-pF capacitor be connected to substitute (replace) a 1-pF capacitor? a. in series b. in parallel c. two in series and one in parallel to them
a. in series
the pressure inside a bubble: a. increase as the bubble radius decreases b. does not depend on bubble radius c. decreases as the bubble radius decreases d. reaches its maximum when the bubble bursts
a. increase as the bubble radius decreases
the electric potential in a point in space is always: a. indirectly proportional to the relative permittivity of the medium b. directly proportional to the user of permittivity of the medium c. indirectly proportional to the square of permittivity of the medium
a. indirectly proportional to the relative permittivity of the medium
which could be a common air pressure on top of Everest: a. less than 50 pKa b. about 10 pKa c. about 100 pKa d. less than 100 mmHg
a. less than 50 pKa At sea level = 100 kPa top of Mount Everest = slightly over 30 kPa
the Illuminance is defined as: a. luminous intensity of a unit area. b. luminous flux incident on an area of 1 steradian. c. luminous flux incident equally on an area of an illuminated body.
a. luminous intensity of a unit area.
the magnitude of ACCELERATION of the body doing simple harmonic association is: a. maximum when reaching maximum displacement b. maximum when reaching zero displacement c. maximum when reaching a displacement equal to half of the amplitude d. constant
a. maximum when reaching maximum displacement
which group units contains only base SI units? a. mole, ampere, candela, second b. mole, amper, candela, joule c. joule, newton, ampere, meter
a. mole, ampere, candela, second
an optical system made of only one converging lens formed a virtual image. this image: a. must be magnified b. cam be magnified c. can be inverted d. cannot form by a converging lens
a. must be magnified
the wavelength of de Broglie waves can be represented by ratio: a. of plank constant and momentum of the particle b. of energy and mass of the particle c. of position and mass of the particle d. of oscillation period and momentum of the particle
a. of plank constant and momentum of the particle
the most frequent way how to utilize the PN junction in semiconductors is an electronic circuit called: a. one-way rectifier b. current amplifier c. emitter d. voltage transformer
a. one-way rectifier
alternating electric current of very LOW frequency passes through a capacitor, but: a. poorly b. only in positive half-waves c. only in negative half-waves d. we must use high-quality dielectric in the space between the plates
a. poorly
if we double the temperature in an isochoric process the: a. pressure double b. volume decrease to half c. volume doesn't change d. pressure decreases to half
a. pressure double
the energy of the electrons in electron orbitals is given mainly by the: a. principle quantum number n. b. orbital momentum quantum number 1. c. magnetic quantum number n.
a. principle quantum number n.
electric work done during transfer of an electron to infinity is equal to: a. product of electron charge and the electric potential in place where the electron was originally located b. the electric potential in place where the electron was placed originally. c. permittivity of medium
a. product of electron charge and the electric potential in place where the electron was originally located
which of the following equations is FALSE for an ideal gas during isobaric process: a. pv = constant b. V1/T1 = V2/T2 c. p = constant d. V/T = constant
a. pv = constant
the instantaneous velocity of a harmonic oscillator is given by the equation.. where y is the amplitude of oscillation.. at the time t = 0 the value v will: a. reach the maximum b. reach the minimum c. be zero
a. reach the maximum
a body doing simple harmonic oscillation has the MINIMUM 'KINETIC ENERGY' in the moment when: a. reaching the maximum acceleration b. traveling through its equilibrium position
a. reaching the maximum acceleration
the wavelength of ultraviolet light is: a. shorter than approximately 400 nm b. in the range 400-800 nm c. longer than approximately 800 nm d. longer than approximately 800µm
a. shorter than approximately 400 nm
in a reversible isobaric compression of a perfect gas, we can find a decrease in: a. temperature and volume b. volume and pressure c. pressure and temperature
a. temperature and volume
the force due to liquid pressure acting on the bottom of a water filled vessel is proportional to only: a. the bottom area and depth, liquid density and free fall acceleration b. the liquid density in free fall acceleration c. the depth of water and liquid density d. the depth of water, liquid density and free fall acceleration
a. the bottom area and depth, liquid density and free fall acceleration
the work done during the transfer of unit electric charge between two points in an electric field equal to: a. the electric voltage b. the dielectric constant of the medium c. the electric field strength d. the value of the electric dipole
a. the electric voltage
the image seen on TV-screen can be locally deformed by a magnetic because: a. the magnetic influences trajectory of the electron beam which "draws" on the screen. b. the magnetic field deflects photon of visible light. c. the luminescent layer of the screen is magnetic d. the magnet attached to the screen influences the orientation of the deflecting coil.
a. the magnetic influences trajectory of the electron beam which "draws" on the screen.
in common light microscope: a. the objective forms a virtual image b. the objective forms an upright image c. the objective forms a real inverted image
a. the objective forms a virtual image
a part of the energy of a violet light photon turned to another form of energy when traveling through a medium: a. the resulting photon can be a photon of yellow light b. the resulting photon can be a photon of ultraviolet light c. there is no reason of color change.
a. the resulting photon can be a photon of yellow light
in a physical process a part of photon energy transformed in some other form of energy: a. the resulting photon cannot be a photon of green light b. the resulting can be a photon of ultraviolet light c. there is no need of light wavelength change
a. the resulting photon cannot be a photon of green light
a part of the energy of a red light photon turned to another form of energy when traveling through a medium: a. the resulting photon cannot be a photon of yellow light. b. the resulting photon can be a photon of violet light. c. there is no reason for color change.
a. the resulting photon cannot be a photon of yellow light.
if we increases the voltage across the plates of the capacitor (in a direct current circuit): a. the size of the electric charge on the capacitor plates increase. b. the capacitance of the capacitor increase. c. the capacitance of the capacitor decrease.
a. the size of the electric charge on the capacitor plates increase.
A short horizontally oriented outlet tube is attached near the bottom of a revolvable cylindrical vessel full of a perfect liquid. the outlet tube is tangent to the cylinder. when the liquid starts to flow out of the vessel: a. the vessel starts turning and the rotation rate will stabilize at the value equal to the speed of the liquid flowing out. b. the vessel starts turning at an ever growing speed.
a. the vessel starts turning and the rotation rate will stabilize at the value equal to the speed of the liquid flowing out.
when a ray of light moves from vacuum to glass: a. there will be refraction towards the normal b. the angle of refraction is always bigger than the angle of incidence c. the angle of refraction is always smaller than the angle of incidence
a. there will be refraction towards the normal
hydrostatic pressure of a liquid measured at the bottom of a vessel is proportional: a. to the bottom depth, liquid density and gravitational acceleration b. to the bottom depth only c. to the bottom depth and liquid density only d. to the liquid density and gravitational acceleration only.
a. to the bottom depth, liquid density and gravitational acceleration
if we increases three time the pressure of a perfect gas in a reversible isochoric (v=constant) process, we obtain: a. triple temperature b. triple volume c. no change in temperature d. a volume decreased to one third.
a. triple temperature
the total reflection of light cannot occur: a. when a light beam passes from a medium with a lower index of refraction to a medium with a higher index. b. when the angle of refraction is smaller than the angle of refraction.
a. when a light beam passes from a medium with a lower index of refraction to a medium with a higher index.
if the plates of a capacitor are moved closer together to half the original distance. the capacitance: a. will increase twice b. will decrease in half c. will increase by half of the original value d. will stay constant
a. will increase twice
the magnitude of the work done by an ideal gas when pushing a piston is given by the formula (assume an isobaric process): a. W = p.v b. W = p/v c. W = p.(V2 - V1) d. W = Q/S
c. W = p.(V2 - V1)
the impedance of an AC circuit involving only the coil increases when: a. decreasing the self-inductance of the coil. b. increasing the self inductance of the coil. c. connection the resistor parallelly.
b. increasing the self inductance of the coil.
a constant current transported an electron charge of 3.6c through a conductor during 3 minute. what was the magnitude of the current? a. 0.6 A b. 0.02 A c. 0.01 A
b. 0.02 A
1 tonee (metric ton) is the same as: a. 100 kg b. 10^12 µg c. 10^9 ng d. 10^12 pg
b. 10^12 µg (meu g)
what is the right Conversion: a. 10A = 10^11 nA b. 1h = 3.6 x 10^12 ns c. 1kJ = 1 watt-hour
b. 1h = 3.6 x 10^12 ns
what is the increase of the sound intensity level if the sound intensity increases 1000 times? a. 1000 dB b. 30 dB c. 10 dB d. 3 dB
b. 30 dB
find the true statement about sound and ultrasound: a. ultrasound has longer wavelength than sound (in water) b. Acoustic oscillations with frequency of 100 kHz can be called ultrasound c. sound does not propagate in liquid by longitudinal wave as a rule d. ultrasound does not propagate in air
b. Acoustic oscillations with frequency of 100 kHz can be called ultrasound
the fact that bubbles of gas always move upwards towards a water surface can be explained using: a. Bernoulli's equation b. Archimedes's law c. Pascal's law
b. Archimedes's law
if the number of neutrons in a nucleus decreases by one, is is possible that only one of the following particle is emitted: a. alfa b. B+ c. B- d. gamma
b. B+
.An ideal gas cannot perform volumetric work during an: a. Isothermal process b. Isochoric process c. Isobaric process d. Adiabatic process
b. Isochoric process
which answer can represent the physical dimension of the universal gas constant? a. J.K.mol b. J.K^1.mol^-1 c. J.K d. J.K^-1 e. no answer is correct
b. J.K^1.mol^-1
when a boron atom is positioned in a silicon Crystal lattice we obtain a semiconductor of the type: a. P-N b. P c. N
b. P
Watt per square meter (Wm-2) is the unit of: a. loudness of sound b. Sound intensity c. Acoustic power d. Acoustic pressure
b. Sound intensity
accommodation of the human eye is caused by: a. a change in curvature of the cornea b. a change of the curvature of the lens c. a change in the diameter of the pupil
b. a change of the curvature of the lens
a significant and consequent interference of X-ray takes place in: a. magnetic field b. crystals c. glass/vacuum interface d. electric field
b. crystals
what is the true meaning of the symbol λ in the law of radioactive decay: a. wavelength of radiation emitted b. decay (disintegration) constant c. half-life time of decaying nuclei
b. decay (disintegration) constant λ = decay constant
a B+ particle was emitted from atom nucleus. it result in: a. increase of neutron number of the nuclide b. decrease proton number by 1 c. decrease of nucleon number by 2 d decrease neutron number by 1
b. decrease proton number by 1
During a reversible isothermal expansion of an ideal gas its pressure: a. increase b. decreases c. Remains constant d. And volume are growing
b. decreases
the magnitude induction Near a straight wire carrying a direct-current is: a. dependent on the metal from which the conductor is made b. directly proportional to the magnitude of the current c. directly proportional to the length of the conductor d. equal to zero
b. directly proportional to the magnitude of the current
which of the following quantities is dimensionless? a. electric capacity b. efficiency c. absolute air humidity d. area e. no answer are correct
b. efficiency is a dimensionless quantity
the term 1/2 P.V^2 involved in the Bernoulli's equation has the same physical dimension as: a. pressure b. energy c. force d. volume
b. energy
an ideal liquid flows out of a short flexible horizontal tube at the bottom of a vessel. if we turn the tube upwards and we neglect the friction, the liquid spurts upwards to a level: a. higher than the level of liquid in vessel b. equal to that of the level of liquid in the vessel c. to the hight of the level of liquid in the vessel divided by the square root of two d. equal to half that of the level of liquid in vessel
b. equal to that of the level of liquid in the vessel
the relative electric permittivity value cannot be: a. positive b. 80 c. 1 d. 0.5
d. 0.5
intensity of electric field: a. directly proportional to its relative permittivity b. indirectly proportional to its relative permittivity c. indirectly proportional to its potential
b. indirectly proportional to its relative permittivity
In which of the following processes will the pressure not decrease when the volume is increased? a. isometric b. isobaric c. isochoric d. adiabatic
b. isobaric constant pressure
the expression v/t is constant in a reversible: a. isothermal process b. isobaric process c. isochoric process
b. isobaric process
in the perfect gas at constant amount of substance, the internal energy of the gas can change during: a. isothermal process b. isobaric process c. diabetic process d. all of the previous cases
b. isobaric process isobaric = pressure is constant
A projectile is fired from ground level under an elevation angle of 60 degrees. when fired under another angle (air friction and inhomogeneity of the gravitation field are neglected) a. it can attain greater higher and can hit the ground in greater distance in the same trial. b. it can hit the ground in greater distance and (at another elevation angle) can attain greater height.
b. it can hit the ground in greater distance and (at another elevation angle) can attain greater height.
increasing pressure in a gas during isochoric process two-times: a. its volume decrease to one half b. its temperature increase two-times c. its temperature decrease to one half d. its temperature remain constant
b. its temperature increase two-times
what unit is the correctly expressed by means of the other units? a. watt [VA-1] b. joule [kgm^2s^-1] c. watt [Js] d. decibel [Wm^-2]
b. joule [kgm^2s^-1]
angular momentum unit: a. kgms b. kgm^2s^-1 c. kgms^-2 d. Nm^-1
b. kgm^2s^-1
which of the following is a vector: a. frequency b. magnetic flux density
b. magnetic flux density
the frequency of x-rays is always higher than the frequency of: a. gamma ray b. microwave c. a radiation of wavelength above 0.01 nm.
b. microwave
in a process in which the volume remains constant, after increasing the temperature of the perfect gas 4 times: a. pressure increased 2-times b. pressure increase 4-times c. pressure did not change
b. pressure increase 4-times
which group involves only the particles whose trajectory can be easily changed by the action of a magnetic field? a. electron, proton, neutron b. proton, electron, oxygen ion c. electron, photon, meson
b. proton, electron, oxygen ion
a worker pulls up a 50-kg body by means of a hand-operated jack. what is his mechanical power compared to another worker doing the same task without any tools but faster? a. bigger b. smaller c. the same d. cannot be solved
b. smaller
two trolleys travel without friction on a horizontal surface. first trolley mass is 8kg, second trolley mass is 16kg. after pushing away the trolley travel in just opposite direction: a. the 1st trolley travelled at speed of 8m/s and the 2nd trolley at a speed of 16 m/s. b. the 1st trolley travelled at speed of 16m/s and the 2nd trolley at a speed of 8 m/s.
b. the 1st trolley travelled at speed of 16m/s and the 2nd trolley at a speed of 8 m/s.
which statement about the reflection of the refraction of light is true? לבדוק את השאלה a. the angle of incidence is always greater than the angle of refraction. b. the angle of incidence is always equal to the angle of refraction. c. the angle of incidence is always smaller than the angle of refraction.
b. the angle of incidence is always equal to the angle of refraction.
the force buoying up an object in a liquid depends on: a. the mass of the immersed object b. the free-fall acceleration c. the density of the immersed object
b. the free-fall acceleration
it is possible to obtain energy from fission if plutonium-239 because: a.the mass defect per one nucleon in caught nuclides is smaller than in plutonium b. the mass defect per one nucleon in daughter nuclides is bigger than in plutonium c. it easily react with uranium-235 d. it is radioactive
b. the mass defect per one nucleon in daughter nuclides is bigger than in plutonium
the activity of a radioactive source is: a. identical with the radioactive decay constant b. the number of decaying nuclei of the source in one second c. the amount of source which can still decay d. identical with the half life time
b. the number of decaying nuclei of the source in one second (per unit of time)
which of the following sentences expresses correctly the pascal's law? a. the pressure is transmitted in a liquid evenly downwards and upwards. b. the pressure in liquid is uniform in all directions inside the liquid body. c. hydrostatic pressure is uniform in any point of the liquid. d. hydrostatic pressure is directly proportional to the liquid depth.
b. the pressure in liquid is uniform in all directions inside the liquid body.
inside a soup bubble produced at the end of a thin pipe we can measure pressure while slowly letting out the air. During this process: a. the surface tension of the bubble wall will decrease at a constant pressure. b. the pressure inside the bubble will go down. c. the pressure inside the bubble will increase.
b. the pressure inside the bubble will go down.
we can get energy by fission of uranium-235 nuclei because: a. the fission products very easily react with ambient medium b. they are radioactive c. the nuclei of produced nuclides have greater mass differences d. they easily react with heavy water.
b. they are radioactive
the gravitational potential energy formula E = mgh could be used for very precise calculation of the work necessary: a. to lift an object from a very deep pit with a depth of h to the level of the surrounding ground. b. to lift a particle to any height h in a homogenous field of gravity.
b. to lift a particle to any height h in a homogenous field of gravity.
a body doing simple harmonic oscillations has the MINIMUM 'POTENTIAL ENERGY' in the moment when: a. reaching maximum acceleration b. traveling through its equilibrium position
b. traveling through its equilibrium position
W.s can be used as a unit of: a. output b. surface tension c. efficiency d. energy
e. energy
what is true sentence about sound and ultrasound? a. sound are longitudinal in liquid b. when transverse sound wave propagate from the air to the water they become longitudinal c. when transverse sound waves propagate from the water to the air they become longitudinal.
b. when transverse sound wave propagate from the air to the water they become longitudinal
The resistance of a conductor: a) Inversely proportional to its length and cross-sectional area b) Directly proportional to its length and cross-sectional area c) Inversely proportional to it's cross-sectional area and directly proportional to its length d) Depends only on the length of the conductor, its cross-sectional area is not important
c) Inversely proportional to it's cross-sectional area and directly proportional to its length
a converging lens has focal distance of +20 cm. what is the optical power: a. +5 N b. +5 W c. +5 D d. +0.05 D
c. +5 D
after position change of two particles, their distance increased from 1m to 4m. the gravitational force acting between these particles decreased: a. 2-times b. 4-times c. 16-times d. zero-times
c. 16-times
the original intensity of a sound was just 1.00 W.m^-2. sound level decreased by 50 dB. what is intensity of the sound now? a. -5 Wm^-2 b. 0.50 Wm^-2 c. 1x10^-5 Wm^-2
c. 1x10^-5 Wm^-2
light rays coming from infinity fall on a thin converging lens of optical power 4D. what is the distance in which they intersect? a. 4cm b. 4m c. 25cm d. 40cm
c. 25cm
Kirchoff's first law deals with: a. Electrical charges in electrolytes b. Cottage induction by changes in a magnetic fireld c. Electrical currents at the nodes of electrical circuits d. Voltages in electrical circuits
c. Electrical currents at the nodes of electrical circuits
Normal stress is defined as the: a. Force applied to a unit length of an elastic bar or wire b. Pressure applied to a unit length of an elastic bar or wire c. Force applied on a unit cross-sectional area of a bar or wire d. Pressure applied on a unit cross-sectional area of a bar or wire
c. Force applied on a unit cross-sectional area of a bar or wire
The magnitude of the magnetic field inside a very long cylindrical coil with electrical current can be increased by: a. Lowering the number of turns b. Lowering the number of turns per unit length of coil c. Inserting a material with high permeability into the coil d. Reducing the radius of coil whilst keeping the number of turns per unit length of coil constant
c. Inserting a material with high permeability into the coil
the wavelength of violet light: a. is shorter than 280 nm b. range between 600 and 800 nm c. Is longer than 380 nm
c. Is longer than 380 nm 380-450 = violet light
As the temperature of conductor increases we expect that a. Its electrical resistance will decrease b. Its electrical conductance will increase c. More heat will be released when passing the same electrical current d. Less heat will be released when passing the same electrical current
c. More heat will be released when passing the same electrical current
a car moves at constant velocity and its engine supplies a constant power. which of the following is correct? a. P=Fa b. P=f/v c. P=Fv d. W=P
c. P=Fv
During an isobaric process an ideal gas follows the equation a. pV = const b. VT = const c. V/(nT) = const. d. nRT = const
c. V/(nT) = const.
electrical power unit: a. ohm [VA] b. V/A c. VA d. tela
c. VA *Tesla = magnetic flux density
light patterns seen on a cathode-ray tube are formed by: a. a thin beam of light moving across the screen. b. the projection of an image produced by a photomultiplier located in the back part of the screen. c. a thin beam of electrons moving across the screen.
c. a thin beam of electrons moving across the screen.
let us have particles with the same initial velocity. which of these particles has the least curved trajectory after entering a homogenous electric field? a. proton b. b-partice c. a-particle
c. a-particle
the properties of X-rays are very similar to the properties of: a. ultraviolet light with with very short wavelength b. cathode rays c. accelerated electrons d. infrared radiation
c. accelerated electrons
a transistor usually serves as: a. a thermistor b. an integrated circuit c. an amplifier
c. an amplifier
Archimedes' Principle is the basic principle of: a. the hydraulic lever b. surface tension c. ballooning d. the mercury barometer
c. ballooning
object placed at the bottom of a water-filled vessel are made of the same material and of the same mass but of different shape. which statement is true? a. buoyant force acting on them in is different in all case b. all the bodies act on the bottom with different force c. buoyant force acting on the shape and a lying disc is the same d. buoyant force acting on a sphere is smaller than the force acting on the lying disc
c. buoyant force acting on the shape and a lying disc is the same
the term wL means the: a. capacitance of a capacitor b. coil self-inductance c. coil inductance
c. coil inductance
vowels have the character of: a. simple tones b. higher overtones c. composite tone d. noise
c. composite tone
the total mechanical oscillator is: a. the highest at maximum displacement b. the Lowest at minimum displacement c. constant d. zero at minimum displacement
c. constant A mechanical oscillation is a periodic conversion of energy from potential energy to kinetic energy to potential energy etc
The relative permittivity of water has a value about 80. If we move two charges with the same sign from air to water their mutual repulsion will: a. Increase b. Not change c. decrease d. Decrease only when there is a surplus of anions or cations the water
c. decrease
the total pressure at a depth of 10m below sea level is approximately equal to: a. half of the atmospheric pressure b. equal to the atmospheric pressure c. double the atmospheric pressure
c. double the atmospheric pressure
which if the following consider as melting: a. evaporation of olive oil b. setting of concrete c. drying of frozen laundry d. action of bile acids in fats
c. drying of frozen laundry
it is known that in the so-called pressure cooker you can cook meat until soft much faster than in a common pot. what is the correct substantiation of this fact? a. due to a good fitting of the lid the boiling water can't be cooled by contact of the surface with air. this results in a shorter cooking time. b. the increased pressure inside the cooker cause the water to boil at a temperature higher than normally. c. due to a good fitting of the lid the boiling water does not evaporate and so the meat is immersed in a sufficient amount of boiling water all the time.
c. due to a good fitting of the lid the boiling water does not evaporate and so the meat is immersed in a sufficient amount of boiling water all the time.
which of the quantities is connected with a non-proprer unit? a. intensity of electric field [vxm^-1] b. amount of substance [mol] c. electric charge [Axs^-1] d. heat [J]
c. electric charge [Axs^-1]
the number of neutrons in an atomic nucleus increased by one, without changing the total number of nucleus. is caused by: a. capture of a neutron b. emission of an electron c. emission of positron d. emission of alpha-particle
c. emission of positron
In the universal gas law, the term nRT related to: a. volume b. pressure c. energy
c. energy
in thermodynamics, the term kt (boatsman constant) related to: a. volume b. pressure c. energy
c. energy
which of the following processes is not an example of sublimation: term-156 a. evaporation of solid carbon dioxide b. drying of frozen washing c. formation of black soot by a burning candle in condition of low air supply
c. formation of black soot by a burning candle in condition of low air supply
pressure of an ideal gas was increased 4-times at the isothermal precess in a vessel closed by a movable piston: a. gas volume decreased to one fourth b. gas temperature decreased to one fourth c. gas volume decreased to one half d. gas volume increased 4-times
c. gas volume decreased to one half
X-rays originate when: a. neutrons are decelerated in a moderator b. light photons are absorbed in a medium c. hitting heavy atoms by fast electrons d. splitting helium nuclei
c. hitting heavy atoms by fast electrons
light rays passing through a thin converging lens intersect in a point which is identical with focus of the lens. the source of light rays is: a. between the front focus and the lens b. in front focus of the lens c. in infinity
c. in infinity
a refrigerator is left with its door open. the temp in the room will: a. decrease b. stay constant c. increase
c. increase
When the pressure in an insulated vessel is lowered, the amount of ice increases compared to liquid water. The temperature: a. Does not change b. decreases c. increases d. First increases and then decreases
c. increases
which of the group quantities contains only vectors? a. density of magnetic flux, acceleration, index of reflection b. pressure, volume, electrical capacity c. intensity of gravitational field, intensity of electric field, momentum
c. intensity of gravitational field, intensity of electric field, momentum
oil film on water can exhibit spectrum colors because of: a. light reflection from the oil surface b. polarization of light c. interference of light on a thin layer d. total reflection of light from the interface between oil and water.
c. interference of light on a thin layer
a swinging pendulum is in a harmonic oscillatory motion. its velocity reaches maximum, when: a. its displacement equals the square root of its amplitude b. it reaches maximum acceleration c. it reaches minimum potential energy d. its displacement just equals its amplitude
c. it reaches minimum potential energy
if a body is in a free fall in vacuum: a. its kinetic energy does not change and its potential energy decreases. b. its kinetic energy increase and its potential energy does not change. c. its kinetic energy increase and its potential energy decrease.
c. its kinetic energy increase and its potential energy decrease.
in electronics, the common meaning of the abbreviation LED: a. laser energised device b. light electric device c. light emitting diode
c. light emitting diode
the so-called shimmering of air, which can be seen above a roof heated by the sun, is caused by: a. light diffraction in the streaming air. b. interfering coherent sunlight. c. light refraction an interferences between airstreams of different density.
c. light refraction an interferences between airstreams of different density.
the magnitude of the VELOCITY of a body doing simple harmonic oscillation: a. maximum when reaching maximum displacement b. minimum when reaching zero displacement c. maximum when reaching zero displacement
c. maximum when reaching zero displacement
which of the sets contain only vector quantities? a. heat, force, sounds intensity b. magnetic field intensity, acceleration, work c. moment of force, density of magnetic flux, instantaneous velocity d. momentum, capacitance, instantaneous velocity
c. moment of force, density of magnetic flux, instantaneous velocity
in the photoelectric effect a. the energy of photon transforms fully into the energy of secondary photon. b. light is emitted from the conductor carrying an electron current. c. no answer is correct
c. no answer is correct
what is the frequency of the circular motion of an object moving uniformly when it completes the whole circle in half a second? a. 0.5 Hz b. 4pai rad.s^-1 c. no answer is correct
c. no answer is correct
which of the following process is a desublimation? a. formation of tooth tartar b. formation of ice "flowers" on windowpanes in winter c. no answer is correct
c. no answer is correct because 'desublimation' is phase change from Gas to Solid
a practical application of the total light reflection can be encountered: a. car headlights b. laser pointers c. optical fibers
c. optical fibers
the work dine by thermodynamic system while is pushing a piston is proportional to the: a. immediate volume b. temperature c. pressure d. internal energy
c. pressure
the physical quantity called luminous flux is defined as: a. light energy passing through a unit area b. quotient of luminous intensity and spatial angle in which the light is emitted c. product of luminous intensity and spatial angle in which the light is emitted d. product of luminous intensity and the area in which the light is emitted
c. product of luminous intensity and spatial angle in which the light is emitted
Which colour has the longest wavelength? a. green b. blue c. red d. violet
c. red
which group of units contain only base SI units? a. second, joule, candela, mole b. second, ampere, newton, moles c. second, mole, kilogram, candela
c. second, mole, kilogram, candela
in case of collision of two air bubbles of the same size in water, the bubbles join easily. the air pressure inside the bubbles is: a. the sum of the pressure in original bubbles b. slightly bigger than in original bubbles c. smaller than in original bubbles d. the same like in the original bubbles
c. smaller than in original bubbles
Which of the following statements is true? a. ultrasound can propagate only in gases b. ultrasound can propagate only in vacuum c. sound oscillation are not oscillations in a magnetic field
c. sound oscillation are not oscillations in a magnetic field
Which statement is true? a. ultrasound waves at speed of light in vacuum. b. the audible sound wavelength is shorter than ultrasound wavelength in water. c. sounds can travel in longitudinal as well as transverse wave in solids.
c. sounds can travel in longitudinal as well as transverse wave in solids. Through solids, sound can be transmitted as both transverse waves and longitudinal waves.
the basic principle of laser is: a. Einstein's monochromatic effect b. collimation of light in one direction c. stimulated emission of light d. spontaneous emission light
c. stimulated emission of light
what is the principle of laser: a. einstein monochromatic phenomenon b. rectifying of light using a precise mirror c. stimulated emission of photons d. spontaneous emission of electrons
c. stimulated emission of photons
the force buoying up an object in a liquid depends on: a. the mass of the immersed object b. the air pressure c. the density of the liquid d. the total volume of the liquid
c. the density of the liquid
the picture seen on a classical CRT TV screen or a PC monitor can be locally deformed by a magnet because: a. the magnet influences the movement of the electron gun b. the magnetic field defocuses the light spot drawing on the screen. c. the electron beam path can be influenced by the magnetic field.
c. the electron beam path can be influenced by the magnetic field.
Faraday's Constant is the same as: a. the electric charge necessary to deposit one gram of a substance on the cathode. b. the energy necessary to deposit one gram of substance on the cathode. c. the energy necessary to transfer 1 mole of electrons from the electrode to ions contained in the electrolyte.
c. the energy necessary to transfer 1 mole of electrons from the electrode to ions contained in the electrolyte.
what is main difference between sound and ultrasound? a. the speed of ultrasound is higher than the speed of sound b. sound wave are transverse while the ultrasound once are longitudinal c. the frequency of ultrasound is higher than the frequency of sound
c. the frequency of ultrasound is higher than the frequency of sound
the pipe organ is a musical instrument often used in churches, whose sound is produced by means of pipes supplied by air from bellows (blowers). find the correct claim. a. the organ tone pitch depends on the frequency of the airstream coming from the bellows. b. the organ tone pitch depends on the amount of the air coming from the bellows into the pipes. c. the properties of the tone produced by the pipes are given mainly by their length.
c. the properties of the tone produced by the pipes are given mainly by their length. (remember it as the pipe in churches!)
a worker pulls up a body by means of a light system of pulleys. what is his mechanical power compared to a worker doing the same task without ant tool and during the same time? a. bigger b. smaller c. the same
c. the same
when the temperature of an electric conductor increases, then: a. its resistance decrease b. its conductance increase c. the same value of electric current produced more heat than 1s d. the same value of electric current produced less heat than 1s
c. the same value of electric current produced more heat than 1s
an aluminum cube is put into a water filled vessel. it may float if: a. the water is heated to 99 Celsius b. the water is magnetized c. the water is replaced by mercury
c. the water is replaced by mercury
Bubbles have spherical shape because a. they "try to have as small a surface as possible due to surface tension. b. they "try to have as great a surface as possible due to surface tension. c. they lower they surface tension in this way.
c. they lower they surface tension in this way.
the basic function of an active medium of a laser: a. absorption of light with unwanted wavelength b. guidance of light by means of mirroring c. to enable stimulated emission of photon d. to set conditions for spontaneous emission of electron
c. to enable stimulated emission of photon
to describe a reversible diabetic compression of a perfect gas we can write: a. p1 x v1 = p2 x v2 b. v1 / t1 = v2 / t2 c. v1 x t1 = v2 x t2
c. v1 x t1 = v2 x t2 if the temperature increase - so does the volume
at the bottom of a water filled vessel is a spherical body and a rod-shaped body. both bodies are of the same density. which of the following statement is true: a. buoyant force acting on the rod is bigger than the force acting on the sphere. b. buoyant force acting on the rod is smaller than the force acting on the sphere. c. we cannot decide whether the buoyant force acting on them is different.
c. we cannot decide whether the buoyant force acting on them is different.
sounds level value is 80db. It means that the sound intensity is: a. 8 Wm^-2 b. 80 Wm^-2 c. 1 x 10^-8 Wm^-2 d. 1 x 10^-4 Wm^-2
d. 1 x 10^-4 Wm^-2
A bar with cross section of 1cm2 has a Young's modulus of elasticity of 100GPa. What force is needed to increase its relative extension by one tenth of a percent? a. 10 N b. 100 N c. 1 000 N d. 10 000 N
d. 10 000 N
water passing through a pipeline enters a section of pipe with smaller radius. if its speed increases four times the original value what is the ratio of the higher to the lower radius of the pipe? a. 1:4 b. 4:1 c. 1:2 d. 2:1
d. 2:1
a harmonic oscillator from its position of equilibrium Only the initial displacement of a harmonic oscillator from its position of equilibrium harmonic oscillator will return to the same displacement after a phase change of: a. 1 rad b. π/2 rad c. π rad d. 2π rad
d. 2π rad
Sound has intensity 1mWm-2. What is the value of this intensity in decibel (dB)? a. 1dB b. 0.001 dB c. 0.002 dB d. 90 dB
d. 90 dB
the force acting between two electric charges at rest is described by: a. kirchhoff's laws b. Faraday's law c. Ohm's law d. Coulomb's law
d. Coulomb's law
The electrostatic force on a unit electrical charge is numerically equal to the: a. Electric potential b. Value of the electric dipole c. Dielectric constant of the surroundings d. Intensity of the electric field
d. Intensity of the electric field
the First law of thermodynamic: a. a rule describing the spontaneous increase of disorder in isolated system b. a rule describing transformation of heat in free energy c. a rule describing spontaneous decrease of disorder in an isolated system d. a special application of the law of conversation of energy
d. a special application of the law of conversation of energy
find the thermodynamic process during which temperature can be lowered at constant pressure, volume and amount of substance: a. isothermal b. isobaric c. isochoric d. adiabatic
d. adiabatic (Temperature decreases during adiabatic expansion)
the mechanical (volumetric) work can be done by perfect gas during: a. isothermal process b. isobaric process c. diabetic process d. all the three previous cases
d. all the three previous cases
which unit is correctly expressed by means of the other units? a. watt [VA-1] b. joule [kgms-2] c. kelvin [Js] d. becquerel [s-1]
d. becquerel [s-1]
the image created by a lens is upright and virtual. the lens: a. cannot be diverging lens b. cannot be converging lens c. can be only diverging lens d. can be both a diverging as well as a converging lens
d. can be both a diverging as well as a converging lens
which of the following gases or gasenoum mixtures has the higher density: a. helium b. oxygen c. air d. carbon dioxide
d. carbon dioxide
unit can be expressed as a product of second and ampere? a. volt b. watt c. joule d. coulomb
d. coulomb
which of the following is dimensionless quantity: a. farad b. becquerel c. light year d. decibel
d. decibel (also efficiency)
in bubble rising to water surface, the buoyant (uplift) force acting on them (consider influence of hydrostatic pressure): a. equal zero, because the bubbles rise freely b. remains constant c. increase d. decrease
d. decrease
a B- particle was emitted from an atom nucleus. it resulted in: a. increase of neutron number of the nuclide b. decrease of proton number by one c. decrease of nucleon number by 2 d. decrease of neutron number by 1
d. decrease of neutron number by 1
the flow rate of liquid flowing from an opening in a bottom of a vessel definitely depends on: a. the total liquid volume b. liquid density c. size of opening d. depth of the liquid
d. depth of the liquid
which of the following is measured in farad? a. self-inductance b. electric current in electrolyte c. magnetic force d. electric capacity
d. electric capacity
which of the following quantities is measured in Farad? a. self-inductance b. electric current in electron c. magnetic force d. electric capacity
d. electric capacity
quantity of [kg·m·s-2]: a. moment of fotce b. acceleration c. momentum d. force
d. force
the electrostatic force between two units of electrical charge is: a. proportional to the distance between them b. proportional to the permittivity of the surrounding medium c. equal to the electrical potential d. given by the expression 1/(4πerª)
d. given by the expression 1/(4πerª)
Peter lifts a load by means of simple pully. what is Peters average power during this work in comparison with Joseph's power who does the same by means of "block and tackle" (a system of two or more pulleys with a rope between them), but during the same time? a. solution is ambiguous b. smaller c. the same d. greater
d. greater
which of the following particles is not influenced by electric field? a. B-particle b. any lepton c. proton d. hydrogen atom
d. hydrogen atom *** also Helium atom!!! Hydrogen Is feebly repelled by magnetic forces
the upward force on a body which is totally submerged will be bigger: a. in the castoff a ball with diameter 1m than in the case of a cube of edge 1m b. in the case of a ball than a cube with the same volume c. in the case of a cube than a ball with the same volume d. in the case of a cube of edge 1m than a ball with diameter 1m
d. in the case of a cube of edge 1m than a ball with diameter 1m
ice was mixed with salt in a thermally insulated vessel, which resulted in its partial melting. during that, its temperature: a. did not change b. lowered by several degrees c. increases=d by several degrees d. increased at first and then lowered
d. increased at first and then lowered
bubbles are ascending up to the surface liquid. the upward force on them will be: a. decreasing b. zero c. constant d. increasing
d. increasing
the illuminance unit is: a. lumen b. candela c. Wm^-2 d. lux
d. lux (lx)
electromagnetic radiation with wavelength longer than infrared radiation is called: a. red light b. visible light c. ultraviolet light d. microwave light
d. microwave light
which of the following is not SI unit (base or derived)? a. mole b. farad c. weber d. minute
d. minute
which group involves only the particles whose trajectory CANNOT be changed by the action of a magnetic field? a. electron, proton, alfa-particle b. proton, neutron, photon c. electron, photon, meson d. neutron, neutrino, photon
d. neutron, neutrino, photon
the surface tension of a liquid is measured by: a. volts b. volts per meter c. volts per meter squared d. newton per meter
d. newton per meter
which of the following can be expressed as a product of the units of force and acceleration: a. watt b. kilogram c. joule d. no answer is correct
d. no answer is correct
what is the true meaning of the symbol Nt in the law of radioactive decay: a. number of atoms decayed during time t b. number of particles emitted during time t c. it should be I d. number of nucleons in the atom nucleus at the end of decay
d. number of nucleons in the atom nucleus at the end of decay
alternating electric current of very HIGH frequency passes through a coil, but: a. poorly b. only in negative half-waves c. only its positive half-waves d. only if high-quality dielectric is used in the space between the plates
d. only if high-quality dielectric is used in the space between the plates
which quantity has units [N•m^-2] a. liquid surface tension b. power c. acceleration d. pressure
d. pressure
why do the bubbles grow in size when ascending towards the water level? a. that is a wrong question b. since their surface tension decrease c. since their surface tension increase d. since the ambient hydrostatic pressure decrease in the process
d. since the ambient hydrostatic pressure decrease in the process
Which statement is false? a. we can hear sound wave of frequency 16-20,000 Hz b. sound level is given by decibel c. Airborne sound wave are longitudinal mechanical oscillations d. sound can travel in vacuum
d. sound can travel in vacuum sound CANNOT travel in vacuum
the force due to liquid pressure acting on the bottom of a water filled vessel is proportional to only: a. the bottom area and depth b. the liquid density in free fall acceleration c. the depth of water and liquid density d. the depth of water, liquid density and free fall acceleration
d. the depth of water, liquid density and free fall acceleration
a (test) point electric charge was moved away from another point charge in the shortest way. the charges had opposite signs. thus: a. the intensity of the electric field didn't change along the path of the test charge. b. the electric potential didn't change along the path of the test charge. c. the intensity of the electric field increased along the path of the test charge. d. the electric potential changed along the path of the test charge.
d. the electric potential changed along the path of the test charge.i
if an ion moves in a homogenous magnetic field from its North Pole to its South Pole: a. it is decelerated uniformly b. it is accelerated uniformly c. it turns in the direction of the thumb of the left hand whose fingers are oriented like B. d. the magnetic field does not influence its motion
d. the magnetic field does not influence its motion
a car travels up a ramp 100m long to height of 5m in 20s. a. about 6.67-fold smaller b. the same c. 3 times smaller d. twice as great
d. twice as great
the total span of sound billet of a healthy human ear is around: a. 16-20,000 dB b. up to 80 dB c. up to 100 dB d. up to 130 dB
d. up to 130 dB
in an isothermal process, after increasing the pressure of the perfect gas 4-times: a. temp. decreased to one half b. volume increased 4-times c. volume decreased to one half d. volume decreased to one fourth
d. volume decreased to one fourth
which of the following quantities is a vector? a. frequency b. magnetic flux density c. capacity of capacitor d. gas pressure e. No answer is correct
e. No answer is correct
an electrically charged particle moves in a magnetic field perpendicular t the direction of the magnetic induction vector B. how does it influence its trajectory? a. it is deflected in the direction of vector b. b. it is deflected opposite in the direction of vector b. c. its movement will be slowed down d. its speed increase e. no answer is correct
e. no answer is correct
find true statement about sound and ultrasound: a. ultrasound propagates also through vacuum b. sound is of shorter wavelength than ultrasound c. ultrasound propagates in solids in form of longitudinal waves d. the ultrasound velocity in air is higher than 20000 m.s^-1 e. no answer is correct
e. no answer is correct
if the light ray passes from glass into vacuum: a. refraction towards the normal occurs. b. refraction away from the normal occurs. c. no refraction occurs. d. total internal refraction occurs. e. no answer is correct
e. no answer is correct
the photoelectric effect is the: a. transmission of electric energy into light b. liberation of photons from electrically charged atomic nuclei c. capture of a photon by a nuclear proton d. production of light by an electric discharge e. no answer is correct
e. no answer is correct
the unit of illumination (illuminance) is: a. lumen b. candela c. W.m^-1 d. lux second e. no answer is correct
e. no answer is correct
what is the main differences between sound and ultrasound: a. the speed of ultrasound is higher than the speed of sound b. sound wave are mechanical character while the ultrasound ones are of electromagnetic character c. sound waves are transverse while ultrasounds are longitudinal d. the oscillator has only potential energy e. no answer is correct
e. no answer is correct
quantity can be expressed like: [kg · m · s^-1] a. torque b. acceleration c. momentum d. force
kg · m · s^-1 is the standard unit of momentum
power unit
kg*m/s
Newton (unit)
kg*m/s^2
What is the unit of momentum?
kgms-1
SI units
kilogram meter second kelvin (absolute temperature) mole (amount of substance) ampere (I = current) candela (intensity of light)
Luminous flux measured in
lumens (lm)
in the direct current, we reduce the voltage across the plates of the capacitor. it cause that: a. the amount of the net electric charge induced on each of the capacitor plates increases. b. the capacitance of the capacitor decrease. c. the capacitance of the capacitor decrease d. the amount of the net electric charge induced on each on each of the capacitor plates decreased
not sure... d. the amount of the net electric charge induced on each on each of the capacitor plates decreased
Photoelectric Effect (Einstein)
phenomenon in which light can be used to knock electrons out of a metal; can be explained only in terms of the particle nature of radiant energy
angular velocity unit: a. Ns-1 b. S-1 c. rads-1 d. rad-1
rads^-1
Becquerel unit
s-1