PHYSICS 131 EXAM 3 QUESTIONS AND ANSWERS
How is the energy stored in a current-carrying inductor related to the current value, I? -
Answers - directly proportional to I^2
When a voltage is generated by rotating a coil in a magnetic field at a constant rate, the
period of the voltage equals the time that it takes for the coil to rotate through ________
radians. - Answers - 2π
By what factor is the self-inductance of an air solenoid changed if only its cross-
sectional area, A, multiplied by eight? - Answers - 8
A circular loop is suspended in a uniform magnetic field as shown in the figure.
If the loop area increases, what affect does this have on the induced current? -
Answers - The induced current is counterclockwise.
Electricity may be generated by rotating a loop of wire between the poles of a magnet.
The induced current is greatest when... - Answers - the plane of the loop is
perpendicular to the magnetic field.
If the induced current in a wire loop were such that the flux it produces were in the same
direction as the change in external flux causing the current, which of the following
conservation laws would end up being violated? - Answers - energy
The operation of an electric motor depends on which of the following effects? - Answers
- the force acting on a current-carrying wire in a magnetic field
An inductor, battery, resistance, and ammeter and switch are connected in series. If the
switch, initially open, is now closed, what is the current's final value? - Answers - battery
voltage divided by resistance
The units T·m2/s are equivalent to: - Answers - V
The function of the electric motor is which one of the following conversion processes? -
Answers - electrical energy to mechanical
The magnet moving past an object will produce eddy currents in the object if the object:
- Answers - is a conductor.
A changing current in one loop of wire can induce a current in another loop of wire even
though the wires do not touch. The induced current appears almost instantaneously for
How is the energy stored in a current-carrying inductor related to the current value, I? -
Answers - directly proportional to I^2
When a voltage is generated by rotating a coil in a magnetic field at a constant rate, the
period of the voltage equals the time that it takes for the coil to rotate through ________
radians. - Answers - 2π
By what factor is the self-inductance of an air solenoid changed if only its cross-
sectional area, A, multiplied by eight? - Answers - 8
A circular loop is suspended in a uniform magnetic field as shown in the figure.
If the loop area increases, what affect does this have on the induced current? -
Answers - The induced current is counterclockwise.
Electricity may be generated by rotating a loop of wire between the poles of a magnet.
The induced current is greatest when... - Answers - the plane of the loop is
perpendicular to the magnetic field.
If the induced current in a wire loop were such that the flux it produces were in the same
direction as the change in external flux causing the current, which of the following
conservation laws would end up being violated? - Answers - energy
The operation of an electric motor depends on which of the following effects? - Answers
- the force acting on a current-carrying wire in a magnetic field
An inductor, battery, resistance, and ammeter and switch are connected in series. If the
switch, initially open, is now closed, what is the current's final value? - Answers - battery
voltage divided by resistance
The units T·m2/s are equivalent to: - Answers - V
The function of the electric motor is which one of the following conversion processes? -
Answers - electrical energy to mechanical
The magnet moving past an object will produce eddy currents in the object if the object:
- Answers - is a conductor.
A changing current in one loop of wire can induce a current in another loop of wire even
though the wires do not touch. The induced current appears almost instantaneously for
