Physics Exam
Which of the following will induce a voltage in a loop of wire?
All of the above except C
Rays of light traveling through different media hit the boundary between the media and the air. The angle of incidence is the same in each case. Which medium has the largest index of refraction?
D
Convex mirror
Diverging mirror
An ohm is equal to which of these?
a volt per ampere
The field lines due to two spheres with like charges are shown by ___.
b
A ray of light traveling in a calm pond strikes the surface at an angle of incidence which is 5° less than the critical angle. This ray will
be refracted away from the normal to the surface in the air.
The rear view mirror of an auto bears the legend "Objects in mirror are closer than they appear". This mirror is a ______ mirror.
diverging
A nearsighted person requires glasses with lenses that are
diverging, to see distant objects.
The magnetic field lines of a bar magnet
emerge from the north pole and go into the south pole
Two light bulbs are installed in two sockets, the sockets are connected in series, and power is then applied to the combination so that both bulbs light. If one of the bulbs is then removed from its socket, the other one will
go out.
Electrons flow around a circular wire loop in a horizontal plane, in a direction that is clockwise when viewed from above. This causes a magnetic field. Inside the loop, the direction of this field is
up, toward the viewer.
A loop of wire enclosing an area of 0.03 m^2 has a magnetic field passing through its plane at an angle to the plane. The component of the field perpendicular to the plane is 0.5T, and the component parallel to the plane is 0.8T. The magnetic flus through this coil is?
0.015 wb
Light enters water (n = 1.33) from air. The incident light ray makes a 0.25° angle with the normal to the surface on the air side. What will be the angle made with the normal by the refracted ray on the water side?
0.188°
In the circuit shown, how much current is flowing through the circuit?
0.2 A
Light enters water (1.33n) from air. The incident light ray makes a 0.44 degree angle with he normal to the surface on the air side. What will be the angle made with the normal by the regranted ray on the water side
0.33 degrees
A woman 1.8 m in height wants a plane mirror so that she can view her full height. The minimum vertical size of such a mirror is
0.9 m.
If the distance between two point charges is tripled while the size of the charges remains the same, the force between the charges is multiplied by
1/9
A transformer has 200 turns on the primary and 20 turns on the secondary. The primary is connected to a direct current source of 100 millivolts. The voltage in the secondary coil will be
10 millivolts.
A 1 cm object is placed 20 cm from a lens. The lens forms a real and inverted image of size 1.5 cm. What is the focal length of the lens?
12cm
A heater is rated to dissipate 1800 W when connected to a 120 V source. The current drawn by the device is
15 A.
A 75 watt bulb and a 150 watt bulb are connected in parallel and the combination is connected to a 120 V line. The bulb that will glow more brightly is the
150 watt bulb.
Two charges with magnitude Q experience a force F when held a distance r apart. What is the force between two charges of magnitude 2Q held a distance r/2 apart?
16F
A certain kind of light bulb carries 1.5 amperes of current when connected to a 120 Volt AC circuit. What is its power rating?
180 W
An object is placed 20 cm in front of a concave mirror of focal length 10 cm. How far is the image will be formed
20 cm from the mirror.
A transformer is to be used to step up voltage from an alternating current source from 110 V to 220 V. If the primary has 120 turns, then the number of turns in the secondary is
240
he voltage drop across a resistor is 3.0 V for a current of 1 A in the resistor. What is the current that will produce a voltage drop of 9.0 V across the resistor?
3 A
Least current will flow through
30 Ohm resistor
If the distance between two point charges remains constant while the size of one of the charges is quadrupled, the force between the charges is multiplied by
4
An object is placed 15 cm in front of a diverging lens of focal length -10 cm. The image will be located
6.0 cm from the lens.
An object is placed 10 cm in front of a diverging lens of focal length -15 cm. The image will be located
6.0 cm in front of the lens.
A transformer is to be used to step down voltage from an alternating current source from 220V to 110V. If the primary has 120 turns, then the number of turns in the secondary is
60
If your face is 62 cm in front of a plane mirror, where is the image of your face located?
62 cm behind the mirror
Which of the following pictures most accurately shows light refracting through a smooth planar surface between air and water?
A
In the circuit below, if a second identical light bulb is added in series with the first, which of the following would occur?
Both bulbs would shine equally, but dimmer than the circuit with one bulb
A ray of light moves from air into water. Which path most accurately shows the refraction?
C
Which of the following lenses is a diverging (concave) lens?
C
Which of the following pictures most accurately shows light refracting through a smooth planar surface between air and water
C
A horizontal straight wire carries a current from west to east. The resulting magnetic field lines are?
Closed circles perpendicular to the wire directed counterclockwise as viewed from the east
Which of the following optical elements used alone can produce a real image of an object?
Concave mirror
A 1.5 V flashlight battery, a 10 ohm resistor, and a flashlight lamp are available. How should the lamp be connected in a circuit so that it would glow the brightest?
Connect it directly to the battery; don't use the resistor.
You have exactly 4 resistors: one 3 Ω, one 4 Ω, one 5 Ω, and one 6 Ω. How can you combine these to make a 2 Ω resistor? (The symbol Ω stands for "ohm".)
Connect the 3 Ω resistor in parallel with the 6 Ω resistor.
You see a positively charged helium ion in space, and it is at rest with respect to your spacecraft. Since you are studying for the final exam, you decide to experiment. You slowly push the N pole of a bar magnet closer to the helium ion. What happens to the helium ion?
Nothing happens, because the ion is not moving
A loop of wire is oriented in the magnetic field as shown below (the plane of the loop is perpendicular to the direction of the magnetic field). Which of the following is true?
There will be an induced current if the loop is moved either up or down.
A circuit contains two un-equal resistors in parallel
Voltage across each resistor is same
Can you charge an object without actually touching it with another charged object?
Yes, this is an example of charging by induction.
Convex (converging) lenses are worn by
a farsighted person to make rays from a nearby object diverge less strongly.
When a glass rod rubbed with silk acquires a positive charge, the silk acquires
a negative charge
A current flowing through a long, straight wire causes a magnetic field that points
along concentric circles around the wire.
The magnetic pole near the Earth's south geographic pole actually has to be
an N pole because it repels the S pole of your compass needle.
The magnetic pole near the earths north geographical pole actually has to be
an S pole, because it attracts the N pole of your compass needle
The magnetic field lines produced by a current in a straight wire
are directed in concentric circles around the wire
A ray emerges from water (n = 1.33) into air. The light ray will
bend away from the normal on the air side.
A horizontal straight wire carries a current from east to west. The resulting magnetic field lines are
closed circles perpendicular to the wire directed clockwise as viewed from the east.
A shaving mirror and a make-up mirror both magnify the image. Thus, these mirrors are ___________ mirrors.
concave
The cornea of the human eye is an example of a
converging lens.
Concave mirror
converging mirror
Rays from a distant object do not diverge enough for a nearsighted person to focus; this can be corrected with a
converging or positive lens.
Rays from a distant object do not diverge enough for a nearsighted person to focus; this can be corrected with a
diverging or concave lens
Rays from a distant object do not diverge enough for a nearsighted person to focus; this can be corrected with a
diverging or concave lens.
A near sighted person requires glasses with lenses that are
diverging, to see distant objects
Which of the following cannot induce a voltage in a loop wire
expanding or contracting the loop in a region where there is no magnetic field
A fish looks up through the smooth surface of the water at a bear directly above it. To the fish, the bear appears to be
farther away than it really is.
The unaided nearsighted human eye focuses light from a distance object
in front of the retina
The unaided near-sighted human eye focuses light from a distant object
in front of the retina.
Imagine a magnetic field pointing into the plane of this page. An electron moves across the paper from left to right. The direction of the magnetic force on the electron will be
in the plane of the paper and toward the bottom of the page.
A converging (convex) lens
is thicker in the center than the edges.
Imagine that this classroom contains a constant magnetic field that points from the front to the back. In front of you a positive charge is slowly moving horizontally to your left. As you watch, the magnetic force on the charge
is vertically up.
If an electron moves in a magnetic field,
it only feels a force if its velocity vector is not parallel (or antiparallel) to the direction of the magnetic field.
Suppose a fish is observed below the surface of a lake. Looking down from above into the water (n = 1.33) the distance the fish appears below the surface is
less than the fish's actual distance.
Magnetic fields affect
only electric charges in motion.
When a switch is closed allowing current to flow in coil A, the current induced in a nearby coaxial but unconnected coil B will flow
only momentarily and then stop
If a current of negative charge flows in a circle in the direction of one's curled fingers of the right hand, the resulting magnetic field would be in the direction
opposite to the thumb of the right hand.
The long straight wire carries a current. A negative charge moves toward the wire in a direction perpendicular to the wire. The direction of the force on the chase will be
parallel to the wire in the direction of the current
A long straight wire carries a current. A positive charge moves toward the wire in a direction perpendicular to the wire. The direction of the force on the charge will be
parallel to the wire opposite the direction of the current.
In the northern hemisphere, the south pole of a compass needle
points toward the south geographic pole because there is a south magnetic pole there.
Bulb A and bulb B are connected in parallel, and powered by a battery. If bulb A is moved from its socket, bulb B will do what?
remain equally bright
Two wires, each carrying current I, are antiparallel to each other. The two wires
repel each other.
If the image formed by a concave mirror is closer to the mirror than the object is, then, compared to the object, the image will be
smaller and inverted.
A magnet on a frictionless mount would have its magnetic north pole point toward the Earth's geographic
south pole
When light is reflected from a smooth, plane mirror
the angle of reflection is the same as the angle of incidence.
A 12 ohm resistor and a 24 ohm resistor are connected in series with a 6.0 V battery. The correct statement is
the current in each resistor is the same.
You could use two parallel wires to move objects 1 and 2 apart if each wire is embedded in its own object and if
the currents in the wires are in opposite directions.
You could use two parallel wires to move object 1 and 2 closer if each wire is embedded in its own object and if
the currents in the wires are in the same direction
Light from the sun passes through a converging lens and forms an image at
the focal point.
An unmarked resistor is being used in a circuit. To determine its resistance by making voltage and current measurements, one should connect
the voltmeter in parallel with the resistor, and the ammeter in series with the resistor.
A magnetic compass points towards the north geographic pole of the Earth because
there is a south magnetic pole near the north geographic pole.
A cross section of the magnetic field for a current-carrying wire is shown. The direction of the current is
to the left.
In normal use, the image seen through eyeglasses is
virtual
A rod with a positive charge is brought near a positively charged pith ball. The pith ball is suspended from an insulating string. The pith ball
will be repelled by the rod
The graph shows the current through a resistor when different amounts of voltage are applied. The resistance of the resistor is closest to
6 ohms
Which of these is not a possible representation of electric field lines?
B
If an electron is placed at rest near a bar magnet, the electron will
Not move at all.
Current flow around a circular wire loop in a horizontal plane, in a direction that is clockwise when viewed from above. This causes a magnetic field. Inside the loop, the direction of this field is?
Down, away from the viewer
Imagine a magnetic field pointing into the plane of this page. An electron moves across the paper from right to left. The direction of the magnetic force on the electron will be
In the plane of the paper and toward the top of the page
A horizontally moving positive sodium ion enters a magnetic field that points up. The magnetic force pushes the charge out of its original path. When viewed as shown on this page, what direction will the magnetic force point?
Out of the page
In the southern hemisphere, the North Pole of a compass needle
Points away from the south geographical pole because there is a north magnetic pole there
You see a charged helium ion in space, and it is moving with respect to your spacecraft. Since you are studying for the final exam, you decide to experiment. You slowly push a bar magnet closer to the helium ion. What happens to the helium ion?
The force depends on whether it is a positive ion or a negative ion
A ray of light in plastic reaches the edge of the plastic. The medium surrounding the plastic is air and the angle of incidence is larger than the critical angle. What will happen?
The ray will experience total internal reflection, the angle of reflection equaling the angle of incidence.
A ray of light in a plastic reaches the edge of the plastic. The medium surrounding the plastic is air and the angle of incidence is larger than the critical angle. What will happen?
The ray will refract out of the plastic bending towards the normal line
