Physics 1
If v stands for velocity of sound, E is elasticity and d the density, then find x in the equation v=(d/E)^x
-1/2
You are in a lift moving from the 3rd floor to the 12th floor, through a height H. If the elevator. moves at a constant speed without stopping, what is the work performed on you by the elevator? Take your body mass as M.
-MgH
The velocity of sound waves in vacuum is
0
If the unit of force is 10N, that of length is 2m and that of velocity is 100m/sec, then the unit of mass is
0.002kg
The dynamic viscosity of a fluid is 1 Poise. What should one multiply to it to get the answer in N-s/m²?
0.1
The coulomb's force between the 2 point charges 10µC and 5µC placed at a distance of 150 cm is
0.2 N
The melting point of water is:
0°C
If M^aL^bT^c is dimensional formula of momentum, and M^xL^yT^z dimensional formula of energy ,find the value of ax+by-c z .
1
Perfect absorber has absorption coefficient of
1
10⁵ Fermi is equal to
1 Angstrom
1 Pa is equal to
1 Nm⁻²
The relative permittivity of most materials lies between
1 and 10
One thousand electrons, each of which carries a charge of -1.6x10⁻¹² coulomb are removed from an initially neutral pitch ball. The resulting charge on the pitch ball is
1.6x10-15 coulomb
A wooden cube of sides 10 cm each dipped in water. The up thrust of water would be
10 N
The up thrust of water acting on a wooden cube of sides 10cm immersed completely in water is
10 N
At a height of about 30 km, the atmospheric pressure becomes
1000 Pa
At sea level, the atmospheric pressure is about
101.300 Pa
The kinematic viscosity of a fluid is 0.1 Stokes. What will be the value is m²/s?
10⁻⁵
As compared to water, mercury is denser
13.6 times
The density of mercury is
13.6 times of water
A packet contains silver powder of mass 20.23 g ± 0.01 g. Some of the powder of mass5.75g ± 0.01 g is taken out from it. The mass of the powder left back is
14.48 ± 0.02 g
If M^aL^bT^cI^d is dimensional formula of resistance, then the value of 4a+5b+c-2d=0
15
A positive and a negative charge are initially 4 cm apart. When they are moved closer together to that they are now only 1 cm apart, the force between them will be
16 times larger than before
A force 100N acts on a body. If the units of mass and length are doubled and unit of time is halved, then the force in the new system changes to
1600N
There are two bodies X and Y with equal kinetic energy but different masses m and m respectively. The ratio of their linear momentum is-
1:2
The radii of two wires of a same material are in ratio 2 : 1. if the wires are stretched by equal forces, the stress produced in them will be
1:4
If a 1 m long steel wire having area 5 * 10⁻⁵ is stretched through 1 mm by force of 10, 000 N then young modulus of wire is
2 * 10¹¹ N m⁻²
In a wire, when elongation is 2 cm energy stored is E. if it is stretched by 10 cm, then the energy stored will be
25 E
The potential at a point due to a charge is 9 V. If the distance is increased three times, the potential at that point will be
27 V
If M^aL^bT^c is dimensional formula of force, find the value of 2a-b-c
3
The states of matter are
3
The wavelength of sound in air is 10 cm. its frequency is, (Given velocity of sound = 330 ms)
3.3 kilo cycles per second
A boat of 8 meters and 40 meter long floats on water. I 125000 N of cargo is added, it will sink
4 cm
If the unit of force and length are doubled, the unit of energy will be
4 times
What is the energy stored per unit volume in a copper wire, which produces longitudinal strain of 0.1% [Y=1.1x10¹¹ N/m²]
5.5 x 10⁴ J/m³
If the unit of force were 20N, that of power were 1MW and that of time were 1 millisecond then the unit of length would be
50m
The value of electric permittivity of free space is
8.85 x10⁻¹² C²/Nm²
A charged oil drop is stationary between a pair of horizontal parallel plates. If the drop carries a charge 3.2x10⁻¹⁰ coulomb and has a mass 1.6x10⁻¹⁹ kg, then the potential difference between the plates
80 V
If the medium between two charges is air, then the value of constant k in SI units will be
9 × 10⁹ Nm²C⁻²
Sound wave cannot get.
Diffracted
Which of the following is not correct for the condition for work not to be done:
Displacement is zero, though force is non-zero
.... When an object moves through a fluid experience a retarding force is known as
Drag force
Which of the following is the best insulator?
Ebonite
Which of the following is a dimensional constant?
Gravitational constant
Which of the following units denotes the dimensions (ML2/Q2], where Q represents the electric charge?
Henry(H)
For small deformations the stress and strain are proportional to each other. This is called
Hook"s Law
The strain produced in a body by the stress applied to it is directly proportional to the stress within the elasticity limit of the body is called
Hooke's law
Which of the following force is non-conservative?
Human push or pull
The unit of stiffness is:
Newtons per metre
In SI, the unit of stress is
Nm⁻²
The SI unit of power is Young's modulus is
Nm⁻²
Which of the following is not a kind of potential energy?
Nuclear potential energy
A Newtonian fluid is defined as the fluid which
Obeys Newton's law of viscosity
Echo is caused due to of sound.
Reflection
On charging by conduction, mass of a body may
increase or decrease
Mass of the liquid cylinder is equal to its
volume * density
Solids have fixed
volume and shape
The acceleration of the particle performing uniform circular motion is
v²/r
Name the characteristics of the sound that are affected by the change in temperature.
wavelength
If two masses (M & m) are connected on a horizontal plane and a force is applied on the combination, then the tension T depends on
whether force is applied on M or m
The dimensions of kinetic energy is same as that of
work
A positively charged rod is brought near an uncharged conductor. If the rod is then suddenly withdrawn, the charge left on the conductor will be
zero
The modulus of rigidity of water is
zero
A point charge in space is attracted towards a dielectric material because of the
maximization of electrostatics flux
The value of k in coulomb's law depends upon
medium between two charges
Matter changing from a solid to a liquid is called:
melting
Which of the following is NOT a way that matter changes phase?
mixing
(ML⁻¹T⁻²) is the dimensional formula of
modulus of elasticity
The ratio of shearing stress to the corresponding shearing strain is called
modulus of rigidity
Matter is made up of particles known as
molecules
What is the maximum possible number of components of a vector can have
Any number
When an object is totally or partially immersed in a liquid, an up thrust acts on it equal to the weight of the liquid it displaces. This statement is called
Archimedes principle
Pressure is defined as the force per unit ..............over the surface of a body.
Area
Charge is
All of these
Which of the following elastic moduli is used to describe the elastic behaviour of object as they respond to the deforming forces acting on them?
All of these
rad / sec is the unit of
Angular velocity
At which place of the earth, the centripetal force is maximum
At the equator
...... Law of conservation of energy is based upon
Bernoulli's theorem
Which of the following is called a fictitious force?
Centrifugal force
Ampere second is a unit of
Charge
In annihilation process, in which an electron and a positron transform into two gamma rays, which property of electric charge is displayed?
Conservation of charge
The continuity equation is the result of application of the following law to the flow field
Conservation of mass
The force of attraction or repulsion between two charges q1 and q2 at a distance d meters apart is proportional to the product of charges q1 and q2 and is inversely proportional to the distance square between the two charges. Above statement is attributed as:
Coulomb's law
The law, governing the force between electric charges is known as
Coulomb's law
What is the unit for measuring the amplitude of a sound?
Decibel
If a material is heated and annealed, then its elasticity is
Decreased
Elastic body is the body that returns to its original shape after a .........
Deformation
The bubble is stable because the atmospheric pressure inside and outside is
Equal
In a system of units if force (F), acceleration (i) and time (T) are taken as fundamentals units then the dimensional formula of energy is
FAT²
Centripetal force always acts at 90 degrees to the velocity, and away from the centre of the circle.
False
The vibrations in which amplitude of vibrations remains constant are called damped vibration
False
What is the study of the properties of fluids in motion is called
Fluid dynamics
Stress is defined as the .............. per unit area of a material.
Force
How should the force applied on a body be varied with velocity to keep the power of force constant?
Force should be inversely proportional to the velocity of the body
When the vibrations of a body are maintained by its own elastic forces then such vibrations are called
Free vibrations
Bernoulli's equation cannot be applied when the flow is
all of the above
Which of the following substances has a higher melting point than water?
all of the above
Incompressible and non viscous fluid is called
Ideal fluid
Which of the following pairs has the same dimensions?
Impulse and momentum
A force which acts for a small time and also varies with time is called:
Impulsive force
A model aeroplane fastened to a post by a fine thread is lying in a horizontal circle. Suddenly the thread breaks. What direction will the aeroplane fly?
In a straight line at a tangent
The number of significant figures in a pure number 410 is
Infinite
Out of the following materials, whose elasticity is independent of temperature?
Invar steel
Water is different from other substances because:
It is less dense as a solid than liquid
Coulomb's law is true for
all the distances
What happens when some charge is placed on a soap bubble?
Its radius increases
Which of the following is a unit that of force?
Kg.m/sec²
Which of the following statements is false:
Kinetic energy is negative
The displacement of particle moving along x-axis with respect to time is r=at+bt²-ct³. The dimension of c is
LT⁻³
If the Reynolds number is less than 2000, the flow in a pipe is
Laminar
The ratio of the change in dimension at right angles to the applied force to the initial dimension is known as
Lateral strain
The base quantity among the following is
Length
Which of the following is not a unit of time?
Light year
Stress strain relationship for Newtonian fluid is
Linear
In waves, matter in the medium moves forward and backward in the same direction the wave travels.
Longitudinal
Which of the following is the dimension of kinematic viscosity?
L²T⁻¹
The dimensions of kinetic energy is
ML²T⁻²
The dimensional formula of coefficient of viscosity is
ML⁻¹T⁻¹
The formula of friction force F in a liquid was first suggested by
Maxwell
When impurities are added to an elastic substance, its elasticity
May increase or decrease
Quantisation of charge was experimentally demonstrated by
Millikan's oil drop experiment
[ML⁻¹ T⁻²] is the dimensional formula of
Modulus of elasticity
Which of the following have the same dimensions as Plank's constant?
Moment of momentum
Which of the following physical quantities has different dimensions?
Momentum
Strokes law holds for
Motion through a viscous medium
Which of the following operations with two vectors can result in a scalar
Multiplication
Which of the dimension of dynamic viscosity?
M¹L⁻¹T⁻¹
Dimensional formula of latent heat
M⁰L²T⁻²
Longitudinal strain is possible in the case of
Only solids
In SI units, the unit of pressure is
Pa
In the longitudinal waves the direction of vibration in medium of particle is
Parallel to propagation
A change in the pressure applied to an enclosed incompressible fluid is transmitted undiminished to every portion of the fluid to the walls of its container. It is called..........
Pascal"s Law
Pressure applied at any point of a liquid enclosed in a container, is transmitted without loss to all other parts of the liquid is called
Pascal's Law
The hydraulic press works on the principle of
Pascal's law
Which one of the following is the CGS unit of dynamic viscosity?
Poise
Which of the following is not the application of ultrasonic?
Radar
In magnitude hydraulic stress is equal to
hydraulic pressure
Coulomb's law is only true for point charges whose sizes are
very small
Stokes law hold for bodies of
Spherical shape
Energy is not carried by
Stationary wave
Which of the following is a unit of kinematic viscosity?
Stokes
Which one of the following is not a unit of dynamic viscosity?
Stokes
Is the ratio of change in dimensions to the original dimensions.
Strain
Zero error in an instrument introduces
Systematic error
We can reduce random errors by
Taking large number of observations
(Density/mass) is equal to
volume
When the intermolecular distance increases due to tensile force, then
There is an attractive force between the molecules
What does fluid means?
To flow
In waves, matter in the medium moves back and forth at right angles to the direction the wave travels.
Transverse
Elasticity is the property of solid materials to return to their original shape and size after the removal of deforming forces.
True
In Simple Harmonic Motion, acceleration is directly proportional to displacement
True
Railway tracks are banked at the curves so that the necessary centripetal force may be obtained from the horizontal component of the reaction on the train
True
Restoring force is the force exerted on a body or a system that tends to move it towards an equilibrium state.
True
Sound waves cannot travel in outer space because these are mechanical waves.
True
The minimum distance of an obstacle for echo to be heard is 16.6 m
True
Wave is a form of disturbance.
True
Which type of waves does not require matter to carry energy?
Ultrasonic waves.
... The internal fraction of fluid is known as
Viscosity
Property of fluid that describes its internal resistance is known as:
Viscosity
In the above question dimensions of b/c are the same as those of
Wave velocity
Is the distance from the top of one crest of a transverse wave to the top of the next crest in that wave
Wavelength
When does the potential energy of a spring increase?
When spring is compressed or stretched
The ratio of stress to tensile strain is called
Young's modulus
The standing waves can be produced
a and c
An electric field can deflect
a-particles
Two physical quantities whose dimensions are not same, cannot be :
added or subtracted in the same expression
Atmospheric pressure acts in
all of above
The angle through which the outer edge is raised above the inner edge is called
angle of banking
Shearing strain is expressed by
angle of shear
Joule second is a unit of
angular momentum
Streamline and equipotential lines in a flow field
are perpendicular to each other
Longidudinal stress depends on
area
The pressure is defined as the force acting per unit
area
The Earth is surrounded by a cover of air called
atmosphere
Charge is the property associated with matter due to which it produces and experiences
both electric and magnetic effects
A passenger in a moving bus is thrown forward when the bus is suddenly stopped. This is explained
by Newtons first law
Quantisation of charge implies
charge, which is a fraction of a coulomb is not possible.
If an object possesses an electric charge, it is said to be electrified or ... A... When it has no charge, it is said to be ... B... Here. A and B refer to
charged, neutral
When a comb rubbed with dry hair attracts pieces of paper. This is because the
comb polarizes the piece of paper
Copper is highly
conducting
When some charge is transferred to ...A... it readily gets distributed over the entire surface of ... A... If some charge is put on ... B..., it stays at the same place. Here, A and B refer to
conductor, insulator
The ratio of stress to strain is
constant
The molecules of matter are
continuously vibrating
Two charges are placed at a certain distance apart. A brass sheet is placed between them. The force between them will
decrease
To push the liquid up in straw the air pressure inside it is
decreased
If the relative permittivity of the medium increases, the electric intensity at a point due to a given charge
decreases
When a dielectric is placed in an electric field, the field strength
decreases
When the relative permittivity of the medium is increased, the force between two charges placed at a given distance apart
decreases
Mass per unit volume is called
density
The velocity of sound in any gas depends upon
density and elasticity of the gas.
The unit of strain is:
dimension-less
When a body is charged by induction, then the body
does not lose any charge
The elastic or matter waves in a solid are
either longitudinal or transverse.
The maximum limit up to which stress is applied on the body without deformation is called
elastic limit
The property of a body to restore its original size and shape as the deforming force ceases to act is called
elasticity
A region around a stationary electric charge haselectric field
electric field
With the propagation of longitudinal wave through a material medium, the quantities transmitted in the propagation direction are :
energy
With the propagation of longitudinal wave through a material medium, the quantities transmitted in the propagation direction are :
energy.
If a body is negatively charged, then it has
excess of electrons
Physical independence of force is a consequence of
first law of motion
If the weight of an object is equal or less than the up thrust acting on it then the object would
float
We can calculate pressure 'P' by the formula
force/area
Whenever a wave enters from one medium to the another, its
frequency does not change.
The matter whose molecules have random motion and move with very high velocities is
gas
The object will sink if its weight is
greater than up thrust on it
To produce both transverse and longitudinal waves, we can use a
helical spring
As one penetrates a uniformly charged sphere, the electric flied strength E
increases
Newton's first law of motion describes the
inertia
Reynolds number signifies the ratio of
inertial forces to viscous forces
The bulk modulus of a perfectly rigid body is
infinity
When the potential difference across the electric field intensity between the parallel plate air capacitor is doubled, plates
is independent of the potential difference
The speed of sound in a medium depends upon
its elasticity as well as its inertia
SI unit of density is
kgm⁻³
The SI Unit standard for mass is the:
kilograme (kg)
As compare to longitudinal waves, the transverse waves move through solids at a speed of
less than half
Liquids have attractive forces
less than solids
The matter can be filled in any container of any shape is
liquids and solid
When a tuning fork vibrates, the waves produced in tuning the Fork are
longitudinal in stem and transverse in prongs
As compared at sea level, the atmospheric pressure on mountains is
lower
Two spheres A and B of exactly same mass are given equal positive and negative charges respectively. Their masses after charging
mass of A < mass of B
The period of a simple pendulum is independent of
mass of the bob
The unit of strain is
no unit
209. One farad is the same as
one coulomb/volt
One volt is the same as
one joule
The unit of Young's modulus of elasticity is:
pascals
The fourth state of matter is called
plasma
The state of matter in which a gas occurs in its ionic state is known as
plasma
Torr' is the unit of
pressure
A floating object displaces a fluid having a weight equal to the weight of the object as per the
principle of floatation
As per Coulomb's law, the force of attraction or repulsion between two point charges is directly proportional to the
product of the magnitude of charges
All of the following are phases (states) of matter EXCEPT:
putty
The substance which shows no elastic after effect practically is
quartz
Midway between two equal and similar charges, a third equal and similar charge is
remain in stable equilibrium
If both the length and radius of the wire are doubled, then how does the modulus of elasticity change?
remains unchanged
The body is said to be elastic if it
returns to original shape after applying pressure
If the length of a wire is reduced to half, then it can hold the
same load
Electric potential is a
scalar quantity
The change in the shape of a regular boy is due to
shearing strain
If the weight of an object is greater than the up thrust acting on it then the object would
sink
In which of the following state, the molecules do not leave their position?
solid
This matter has a fixed shape and volume with particles closely packed together with little movement. It is a....
solid
Longitudinal waves move faster through
solids
Stone, metal spoon, pencil are examples of
solids
Gases are much lighter than
solids and liquids
From the following, the example of a longitudinal wave is
sound wave
238.The velocity of sound in a gas is proportional to :
square root of the adiabatic elasticity.
A comparison of such a change caused by the stress with the original shape, volume or length is called
strain
The force acting on the unit area on the surface is called
stress
The force acting on unit area of the surface of a body is called
stress
In Hooke's law, constant is equal to
stress/strain
Matter changing from a solid to a gas is called:
sublimation
(Change in length/original length) is equal to
tensile strain
The breaking stress for wire of unit area of cross-section is called its:
tensile strength
The weight of a body is 12g. This statement is not correct because:
the correct symbol for the unit of weight has not been used
Two charged spheres of radii 10 cm and 15 cm are connected by a thin wire. No current will flow if they have
the same potential
A body is positively charged, it implies that
there is positive as well as negative charge in the body but the positive charge is more than negative charge
On the basis of dimensional equation, the maximum number of unknown that can be found, is
three
In order to make an object font, its weight should be equal to
up thrust acting on it
On rubbing, when one body gets positively charged and other negatively charged, the electrons transferred from positively charged body to negatively charged body are
valence electrons only