Exam 30: Induction and Inductance

The normal to a certain 1.0 m² area makes an angle of 60° with a uniform magnetic field.The magnetic flux through this area is the same as the flux through a second area that is perpendicular to the field if the second area is:

A long straight wire is in the plane of a rectangular conducting loop.The straight wire initially carries a constant current i in the direction shown.While the current i is being shut off, the current in the loop is:

A rectangular loop of wire is placed perpendicular to a uniform magnetic field and then spun around one of its sides at frequency f.The induced emf is a maximum when:

The diagram shows an inductor that is part of a circuit.The direction of the emf induced in the inductor is indicated.Which of the following is possible?

1 weber is the same as:

The graph shows the magnitude B of a uniform magnetic field that is perpendicular to the plane of a conducting loop.Rank the four regions indicated on the graph according to the magnitude of the emf induced in the loop, from least to greatest.

An inductance L and a resistance R are connected in series to an ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.The rate of increase of the energy stored in the inductor is a maximum:

A 3.5 mH inductor and a 4.5 mH inductor are connected in series.The equivalent inductance is:

Faraday's law states that an induced emf is proportional to:

An inductance L, resistance R, and ideal battery of emf are wired in series and the circuit is allowed to come to equilibrium.A switch in the circuit is opened at time t = 0, at which time the current is /R.At any later time t the potential difference across the resistor is given by:

When the switch S in the circuit shown is closed, the time constant for the growth of current in R₂ is:

An inductance L, resistance R, and ideal battery of emf are wired in series.A switch in the circuit is closed at time t = 0, at which time the current is zero.At any later time t the current i is given by:

The unit "henry" is equivalent to:

If both the resistance and the inductance in an LR series circuit are doubled the new inductive time constant will be:

The emf developed in a coil X due to the current in a neighboring coil Y is proportional to the:

If the magnetic flux through a certain region is changing with time:

A cylindrical region of radius R contains a uniform magnetic field, parallel to its axis, with magnitude that is changing linearly with time.If r is the radial distance from the cylinder axis, the magnitude of the induced electric field inside the cylindrical region is proportional to:

A 6.0 mH inductor is in a circuit.At the instant the current is 5.0 A and its rate of change is 200 A/s, the rate with which the energy stored in the inductor is increasing is:

A cylindrical region of radius R = 3.0 cm contains a uniform magnetic field parallel to its axis.If the electric field induced at a point R/2 from the cylinder axis is 4.5 *10^-3 V/m the magnitude of the magnetic field must be changing at the rate of:

You push a permanent magnet with its north pole away from you toward a loop of conducting wire in front of you.Before the north pole enters the loop the current in the loop is: