Physical Science Exam 2
What is the wavelength of a 301.1 MHz radio wave?
1.00 m
What is the range of normal human hearing?
20-20,000 Hz
A space heater draws a current of 5 A when connected to a 110-V power source. Its resistance is
22 Ω
Charge moving through a wire produces a magnetic field around the wire
T
Light waves are transverse waves
T
The speed of light in space is 3 x 10^8 m/s
T
The speed of sound in air is temperature-dependent
T
When waves travel from one place to another, they carry energy
T
When astronomers study the light emitted from the Sun they notice that the light emitted from the east edge is blueshifted while the light emitted from the west edge is redshifted. The reason for this is that
The sun is rotating
Direct electric current cannot be used to operate
Transformers
Electromagnetic waves are longitudinal waves
false
The Doppler effect is the change in the wavelength of light caused by the source
moving with respect to the observer
Of the following transitions in a hydrogen atom, which emits the photon of highest frequency?
n=1 to n=2
Of the following transitions in a hydrogen atom, which emits the photon of highest frequency?
n=6 n=1
Compared to the speed of light in deep space, light's speed in water or in glass is
slower
Relative to the electric force between two protons, the gravitational force between them is
weaker
Light of which of the following wavelengths has the highest frequency?
x-ray
Ocean waves with a period of 10 s are found to have a wavelength of 120 m. Their speed is
12 m/s V= d/t V= 120/10
A space heater draws a current of 15-A when connected to a 220-V power source. Its resistance is _________________.
14.7Ω 220V/15A= 14.66
Consider a transformer that has 40 loops on its primary coil and 10 loops on its secondary coil. What is the voltage in the secondary coil if the primary coil is supplied with 120 V?
30 V
A transformer is to be used to step down voltage from an alternating current source from 250 V to 110 V. If the primary coil has a current of 15 A, then the current in the secondary coil is
34.1 A
A transformer is to be used to step down voltage from an alternating current source from 330 V to 110 V. If the primary has 120 turns, then the number of turns in the secondary is
40
The current in a 60-W, 12-V light bulb is
5 A 60W/12V= 5 amps
The current in a 15-Ω electric heater operated at 120 V is
8 A
Electric current is measured in units of
Amp
What unit is used for current?
Amperes
Radio waves travel through space at what speed?
At the speed of light, 2.998 x 10^8 m/s
Thomas Young performed a crucial experiment on the nature of light when he
Demonstrated the wave nature of light passing light through two slits and obtaining a pattern of bright and dark bands on a screen that he correctly interpreted as interference between the two light beams.
The idea that light consists of photons was first proposed by
Einstein
The idea that light consists of photons, bundles of pure energy, was first proposed by
Einstein
A proton in an atom circulates around its nucleus
F
A typical atom is negatively charged
F
Depending on the time of day, the rainbow's colors will be in different orders
F
Opposites charges repel; like charges attract
F
Protons and electrons have equal masses
F
Resistance is measured in Watts
F
Sound waves are transverse waves
F
Who holds the patent for inventing the radio
Guglielmo Marconi
Two waves can combine with each other in a way that either amplifies or cancels out the original light waves. What is this behavior called?
Intereference
You are looking at a penny at the bottom of a fountain that is 2 m deep while standing on a sidewalk above it. To you the penny seems to be
Less than 2 m deep
Coulomb's law for the force between electric charges belongs in the same general category as
Newton's law of gravitation
V=IR is a statement of
Ohm's Law
Resistance is measured in units of
Ohms
Which of the following lists of different types of electromagnetic radiation is correctly ordered in wavelength, from longest to shortest?
Radio, Infrared, Ultraviolet, Gamma rays
Star A is blue, Star B is yellow, and Star C is red. Which one of these is the hottest star?
Star A
To measure a DC current, the circuit must be a closed loop.
T/F
A fire truck is racing towards you. As it is moving toward you, the sound is high pitched, while the sound from the vehicle moving away lowers in pitch. This is an example of
The Doppler effect
The two most important properties of a telescope are
The light gathering power and the angular resolution.
The speed of light in vacuum is constant
True
A ___________ is a disturbance or vibration propagated from point to point in a medium or space.
Wave
White light is
a mixture of all frequencies and all colors of light
In the full wavelength range of electromagnetic radiation, visible light occupies what proportion of this possible range?
a very narrow range
If an electron jumps from a lower energy level in an atom to a higher energy level, a photon is
absorbed
The measure denoted by y is called
amplitude
If you move the north pole of a magnet toward the south pole of another magnet, they will
attract
The electric energy lost when a current passes through a resistance
becomes heat
To an astronaut in orbit many miles above Earth's atmosphere, the sky around them appears
black
What type of lens is this? *diagram is shown
concave
The nucleus of an atom
contains most of the atom's mass
A convex lens causes light to _______________ to a single focal point
converge
A changing MAGNETIC field will induce a
current
Electric power is equal to
current x voltage
When light passes through a prism of glass,
different colors or wavelengths of light are separated by the prism
An electric motor transforms
electrical energy into mechanical energy
The particle easiest to remove from an atom is the
electron
In drawing of magnetic field lines, the weaker the field is, the
farther apart the field lines are
A fast train approaches a car waiting at a grade crossing and sounds its horn. A person in the car will notice that, compared to what it would be if the train were at rest, the horn sound's
frequency appears to be higher
compared to visible light, x rays have
higher frequency and shorter wavelength
A rainbow always appears
in the part of the sky opposite from the Sun
If you want to design a device that will detect animals at night by the radiation they give off, even if the night is totally dark, to what wavelength range should you make the device sensitive?
infrared
The daytime sky is blue, on sunny days, because the atmosphere
is more efficient at scattering blue light
Suppose a fish is observed below the surface of a lake. The distance the fish appears below the surface when looking down from above into the water is
less than the fish's actual distance
The greater the decibel (dB) level of a sound wave, the
louder it is
A changing ELECTRIC field will produce a
magnetic field
The Earth's geographic north pole is a
magnetic south pole
A circuit that has multiple paths for the current to take is referred to as a ______________ .
parallel circuit
In a longitudinal wave, the individual particles of the medium move
parallel to the direction of the wave
In a transverse wave, the individual particles of the medium move
perpendicular to the direction of travel
Which of the following has the least energy, lowest frequency, and longest wavelength?
radio waves
Photons of which of the following colors of light possess the least amount of energy?
red
The color of a relatively cool star is
red
A pencil in a glass of water appears bent. This is an example of
refraction
When light travels from air to glass, it ____________, or bends
refracts
For some Christmas lights, one broken bulb will cause the entire strand to go out. This is because it is a
series circuit
a circuit that has a single path for current to take is referred to as a __________________.
series circuit
In a transformer, if the primary coil contains fewer loops than the secondary coil then it is a
set-up transformer
Gamma rays are dangerous because they are high energy, high frequency, with a _______________ wavelength.
short
A spacecraft is approaching Earth. Compared to the radio signals that it sends out, the signals that you receive on Earth have
shorter wavelength
Visible light as ____________ wavelength and __________ frequency relative to ultraviolet light
shorter; larger
Bill and Fred are out on a spacewalk when Bill's suit communication system goes down. He shouts to Fred about it, but Fred cannot hear him. Why can't Fred hear him?
sound cannot travel through empty space, airless space between them
Of the following kinds of waves, the only one that cannot travel through a vacuum (like outer space) are
sound waves
The sun appears reddish as it sets because
the blue wavelengths have already been scattered by the atmosphere
Electric current is
the flow of charge
When light of a particular frequency hits certain metallic surfaces, electrons are emitted by the surface. This is a description of:
the particle nature of light
A set of Christmas tree lights is wired in parallel. What will happen if one of the lights burns out?
the rest of the lights will stay on
The higher the frequency of a wave
the shorter its wavelength
Why was adaptive optics developed?
to compensate for image distortion caused by Earth's atmosphere
Light can be treated as particle when it is absorbed by electron.
true
The speed of sound depends on temperature
true
Photons of which of the following colors of light possess the most energy?
violet
The measure denoted by λ is called
wavelength