Physics Exam 3 Multiple Choice Bank
Exam Question & Answer Latest
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A resistor is wired in a circuit with a power supply. The current (I) in the circuit is then
measured by an ammeter for various power supply voltage settings (V). V (y-axis) is
then plotted versus I (x-axis) to obtain a best fit straight line. The slope of this line is
found to be 0.5 kilo-Ohms. Now, if the power supply is set to a random voltage of 10
Volts in the circuit with the same resistor and measured, what will be true about the
experiment? - CORRECT ANSWER//The measured current will likely be close to 20
milli-Amps.
A second and a third resistor are now included in the same circuit to conduct the
experiment. What are the possible ways to include them?
a) Wiring all three in series.
,b) Wiring all three in parallel.
c) Wiring 1st and 2nd in series, and 3rd one in parallel with 2nd.
d) Wiring 1st and 2nd in series, and 3rd one in parallel with 1st.
e) All four wirings above are possible. - CORRECT ANSWER//All four wirings above are
possible.
A resistor of 100 Ohms is wired with a power supply so a current in the circuit is
produced. If you are given a second resistor of 200 Ohms and asked to include it in the
circuit such that the net equivalent resistance in the circuit decreases from both 100 and
200 Ohms, so higher current is drawn from the power supply. But you cannot change
the power supply voltage! What could you do? - CORRECT ANSWER//Wire the new
resistor in parallel with the old one.
A power supply set at 12 Volts is wired with two 3-Ohm resistors in series. By the
Kirchoff's voltage rule, 2 Amps of current will flow in the circuit. If you are challenged to
choose a different pair of resistors in the circuit so the current does not change, you
could use:
a) 4 Ohms & 2 Ohms
b) 5 Ohms & 1 Ohms
c) 2.5 Ohms and 3.5 Ohms
d) All above
e) None above - CORRECT ANSWER//d) All above
A 3-Ohm resistor is wired with a 12-Volt power supply creating 4 Amps of current. You
then include another 3-Ohm resistor in parallel with the previous resistor so that 4 Amps
of current also flows through the new resistor. By the Kirchoff's junction rule, how much
current will now be drawn out of the power supply? - CORRECT ANSWER//8 amps
2 Amps of current is drawn out of a power supply (V) that flows through a 1-Ohm
resistor (R) before equally splitting into two parallel branches each containing a 1-Ohm
resistor (R1 & R2). What are the voltages (V, V1, V2 respectively) in Volts across each
resistor that you will measure by a voltmeter? - CORRECT ANSWER//2, 1, 1
The armature coil of a Direct Current Motor will rotate when at least one of the following
will happen: - CORRECT ANSWER//Currents must flow through both the armature and
the field coils
In a DC Motor the available power output for mechanical work equals: - CORRECT
ANSWER//The leftover part of the input power after the power utilized on both field and
armature coils.
Which motor's efficiency is more stable for all voltages and which one is more efficient
at startup (low voltage)? - CORRECT ANSWER//Shunt wound motor and shunt wound
motor
, An induced voltage will produce in the armature coil of a Magneto Generator when one
of the following will happen (pick the most complete answer):
a) The magnetic field lines do not pass through the armature coil.
b) The magnetic field lines do pass through the armature coil.
c) The magnetic field lines pass though the armature coil and the armature rotates at a
constant speed.
d) The magnetic field lines pass though the armature coil and the armature rotates at an
accelerated speed.
e) Both (c) and (d). - CORRECT ANSWER//Both (c) and (d).
A coil of wire is moving to the right through a magnetic field as shown in the figure on pg
#47 in the lab manual. A, B, C, D, E are different positions at different times while it is
moving from the left to the right. In which positions is the induced emf (voltage) in the
coil zero? (Refer to the picture on page #47 of the lab manual) - CORRECT
ANSWER//Position A, C, and E
For your data analysis with 10-Ohm load on Magneto Generator, why did the max and
min of the induced alternating voltage eventually roughly stabilize or changed very
slowly? - CORRECT ANSWER//Because the loss of potential energy of the falling
weight was shared between the gains of the rotational energy and of the electrical
energy through the load.
A light ray in the air incidents on a plane glass-mirror at a certain angle of incidence.
70% of the light reflects back in the air and 30% refracts into the glass. You measure
the angles of incidence, reflection and refraction, and you find that: - CORRECT
ANSWER//The angle of reflection is greater than the angle of refraction
What is true about the focal points of concave and convex spherical-mirrors and
converging and diverging lenses? - CORRECT ANSWER//The focal points of concave
mirror and converging lens are REAL but of convex mirror and diverging lens are
VIRTUAL.
In the telephoto lens lab the combination of a converging and a diverging lens was used
to focus parallel rays of light at a distance by changing the lens separation d. What of
the following was found to happen? - CORRECT ANSWER//When d is increased, the
focal length of the telephoto lens decreases.
The images by a thin converging lens obtained in our experiment were: - CORRECT
ANSWER//Inverted compared to the object.
The images formed in the experiment were: - CORRECT ANSWER//Real because they
were captured on a screen.
If the size of the image is larger than the size of the object then what is true? -
CORRECT ANSWER//The image is farther from the lens than the object is.
Exam Question & Answer Latest
version uploads new version
A resistor is wired in a circuit with a power supply. The current (I) in the circuit is then
measured by an ammeter for various power supply voltage settings (V). V (y-axis) is
then plotted versus I (x-axis) to obtain a best fit straight line. The slope of this line is
found to be 0.5 kilo-Ohms. Now, if the power supply is set to a random voltage of 10
Volts in the circuit with the same resistor and measured, what will be true about the
experiment? - CORRECT ANSWER//The measured current will likely be close to 20
milli-Amps.
A second and a third resistor are now included in the same circuit to conduct the
experiment. What are the possible ways to include them?
a) Wiring all three in series.
,b) Wiring all three in parallel.
c) Wiring 1st and 2nd in series, and 3rd one in parallel with 2nd.
d) Wiring 1st and 2nd in series, and 3rd one in parallel with 1st.
e) All four wirings above are possible. - CORRECT ANSWER//All four wirings above are
possible.
A resistor of 100 Ohms is wired with a power supply so a current in the circuit is
produced. If you are given a second resistor of 200 Ohms and asked to include it in the
circuit such that the net equivalent resistance in the circuit decreases from both 100 and
200 Ohms, so higher current is drawn from the power supply. But you cannot change
the power supply voltage! What could you do? - CORRECT ANSWER//Wire the new
resistor in parallel with the old one.
A power supply set at 12 Volts is wired with two 3-Ohm resistors in series. By the
Kirchoff's voltage rule, 2 Amps of current will flow in the circuit. If you are challenged to
choose a different pair of resistors in the circuit so the current does not change, you
could use:
a) 4 Ohms & 2 Ohms
b) 5 Ohms & 1 Ohms
c) 2.5 Ohms and 3.5 Ohms
d) All above
e) None above - CORRECT ANSWER//d) All above
A 3-Ohm resistor is wired with a 12-Volt power supply creating 4 Amps of current. You
then include another 3-Ohm resistor in parallel with the previous resistor so that 4 Amps
of current also flows through the new resistor. By the Kirchoff's junction rule, how much
current will now be drawn out of the power supply? - CORRECT ANSWER//8 amps
2 Amps of current is drawn out of a power supply (V) that flows through a 1-Ohm
resistor (R) before equally splitting into two parallel branches each containing a 1-Ohm
resistor (R1 & R2). What are the voltages (V, V1, V2 respectively) in Volts across each
resistor that you will measure by a voltmeter? - CORRECT ANSWER//2, 1, 1
The armature coil of a Direct Current Motor will rotate when at least one of the following
will happen: - CORRECT ANSWER//Currents must flow through both the armature and
the field coils
In a DC Motor the available power output for mechanical work equals: - CORRECT
ANSWER//The leftover part of the input power after the power utilized on both field and
armature coils.
Which motor's efficiency is more stable for all voltages and which one is more efficient
at startup (low voltage)? - CORRECT ANSWER//Shunt wound motor and shunt wound
motor
, An induced voltage will produce in the armature coil of a Magneto Generator when one
of the following will happen (pick the most complete answer):
a) The magnetic field lines do not pass through the armature coil.
b) The magnetic field lines do pass through the armature coil.
c) The magnetic field lines pass though the armature coil and the armature rotates at a
constant speed.
d) The magnetic field lines pass though the armature coil and the armature rotates at an
accelerated speed.
e) Both (c) and (d). - CORRECT ANSWER//Both (c) and (d).
A coil of wire is moving to the right through a magnetic field as shown in the figure on pg
#47 in the lab manual. A, B, C, D, E are different positions at different times while it is
moving from the left to the right. In which positions is the induced emf (voltage) in the
coil zero? (Refer to the picture on page #47 of the lab manual) - CORRECT
ANSWER//Position A, C, and E
For your data analysis with 10-Ohm load on Magneto Generator, why did the max and
min of the induced alternating voltage eventually roughly stabilize or changed very
slowly? - CORRECT ANSWER//Because the loss of potential energy of the falling
weight was shared between the gains of the rotational energy and of the electrical
energy through the load.
A light ray in the air incidents on a plane glass-mirror at a certain angle of incidence.
70% of the light reflects back in the air and 30% refracts into the glass. You measure
the angles of incidence, reflection and refraction, and you find that: - CORRECT
ANSWER//The angle of reflection is greater than the angle of refraction
What is true about the focal points of concave and convex spherical-mirrors and
converging and diverging lenses? - CORRECT ANSWER//The focal points of concave
mirror and converging lens are REAL but of convex mirror and diverging lens are
VIRTUAL.
In the telephoto lens lab the combination of a converging and a diverging lens was used
to focus parallel rays of light at a distance by changing the lens separation d. What of
the following was found to happen? - CORRECT ANSWER//When d is increased, the
focal length of the telephoto lens decreases.
The images by a thin converging lens obtained in our experiment were: - CORRECT
ANSWER//Inverted compared to the object.
The images formed in the experiment were: - CORRECT ANSWER//Real because they
were captured on a screen.
If the size of the image is larger than the size of the object then what is true? -
CORRECT ANSWER//The image is farther from the lens than the object is.
