FiltersDone

Question type

Essay

Multiple Choice

Short Answer

True False

Matching

Exam 20: Induced Voltages and Inductance

Show Answer

Share

---

All types

Filters

Study FlashcardsPractice ExamLearn

Question 21

Multiple Choice

Review LaterAdd Note

Review Later

A circular loop (area = 0.20 m²) turns in a uniform magnetic field with B = 0.13 T.At an instant when the angle between the magnetic field and the normal to the plane of the loop is p rads and is decreasing at the rate of 0.50 rad/s, what is the magnitude of the emf induced in the loop?

A) zero
B) 13 mV
C) 26 mV
D) 20 mV

E) B) and C)
F) A) and C)

Correct Answer

verified

Show Answer

Question 22

Multiple Choice

Review LaterAdd Note

Review Later

A square coil, enclosing an area with sides 2.0 cm long, is wrapped with 2 500 turns of wire.A uniform magnetic field perpendicular to its plane is turned on and increases to 0.25 T during an interval of 1.0 s.What average voltage is induced in the coil?

A) 0.25 V
B) 0.12 V
C) 2.0 V
D) 2.5 V

E) B) and D)
F) A) and C)

Correct Answer

verified

Show Answer

Question 23

Multiple Choice

Review LaterAdd Note

Three loops of wire, one circular, one rectangular, and one square, are made from identical lengths of wire.If the loops are in the same increasing magnetic field perpendicular to the plane of the coils, which loop has the greatest induced emf?

An RL series circuit has the following components: 5.0-mH coil, 1.0-W resistor, 12-V battery, ammeter and switch.What is the time constant of this circuit?

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?

The magnet moving past an object will produce eddy currents in the object if the object:

A coil is placed in a changing magnetic field and an emf is induced.What happens to the induced emf if the rate of change of magnetic field quadruples?

A loop of area 0.250 m² is in a uniform 0.020 0-T magnetic field.If the flux through the loop is 3.83 * 10^-3 T·m², what angle does the normal to the plane of the loop make with the direction of the magnetic field?

If a bar magnet is falling through a loop of wire, the induced current in the loop of wire sets up a field which exerts a force on the magnet.This force between the magnet and the loop will be attractive when:

According to Lenz's law the direction of an induced current in a conductor will be that which tends to produce which of the following effects?

The basic function of the electric generator is which of the following conversion processes?

The back emf in an electric motor is its maximum value under which condition?

A metal rod is falling toward the surface of the Earth near the equator.As it falls, one end of the rod becomes positively charged due to the motional emf of the rod through the Earth's magnetic field.The rod is oriented so that:

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.

A 500-turn circular coil with an area of 0.050 0 m² is mounted on a rotating frame, which turns at a rate of 20.0 rad/s in the presence of a 0.050 0-T uniform magnetic field that is perpendicular to the axis of rotation.What is the instantaneous emf in the coil at the moment that the normal to its plane is at a 90.0 $\degree$ angle to the field?

A coil is placed in a magnetic field and has a flux F_B through it.The coil is stressed so that its area reduces to 75% of its original value.If the plane of the coil stays the same and the flux through it remains the same, how must the magnetic field change?

A coil is rotated in a magnetic field generating an emf given by emf = NBAw sin q, where q = wt.At which angle q is the emf half of its maximum value?

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?

A straight wire of length is oriented east-west and is in a magnetic field B pointing north.The wire is moving downward at a constant speed v.If the resistance of the rod is R, what is the current through the rod?

A series circuit contains a 12-V battery, a 2.0-W resistor, and a 3.0-mH inductor.If the switch to the battery is closed at t = 0, find the time required for the current in the circuit to reach 63% of its final value.