Exam 22: Electromagnetic Induction

Two coils,1 and 2,with iron cores are positioned as shown in the figure.Coil 1 is part of a circuit with a battery and a switch. -Assume the switch S has been closed for a long time.Which one of the following statements is true?

Which one of the following combinations of units is equivalent to one henry?

A loop with a resistance of 4.0 is pushed to the left at a constant speed of 2.0 m/s by a 24 N force.At the instant shown in the figure,the loop is partially in and partially out of a uniform magnetic field.An induced current flows from left to right through the resistor.The length and width of the loop are 2.0 m and 1.0 m,respectively. -Determine the magnitude of the uniform magnetic field.

A closed loop carries a current that increases with time.Which one of the quantities listed below relates the emf induced in the loop to the rate at which the current is increasing?

The figure shows a uniform magnetic field that is normal to the plane of a conducting loop with resistance R.Which one of the following changes will cause an induced current to flow through the resistor?

A 0.100-m long solenoid has a radius of 0.050 m and 1.50 × 10⁴ turns.The current in the solenoid changes at a rate of 6.0 A/s.A conducting loop of radius 0.0200 m is placed at the center of the solenoid with its axis the same as that of the solenoid as shown. -Determine the induced emf in the loop.

A circular coil has 275 turns and a radius of 0.045 m.The coil is used as an ac generator by rotating it in a 0.500 T magnetic field,as shown in the figure.At what angular speed should the coil be rotated so that the maximum emf is 175 V?

A small power plant produces a voltage of 6.0 kV and 150 A.The voltage is stepped up to 240 kV by a transformer before it is transmitted to a substation.The resistance of the transmission line between the power plant and the substation is 75 . -What is the current in the transmission line from the plant to the substation?

A circuit is pulled with a 21-N force toward the right to maintain a constant speed v.At the instant shown,the loop is partially in and partially out of a uniform magnetic field that is directed into the paper.As the circuit moves,a 4.0-A current flows through a 6.0- resistor. -Which one of the following statements concerning this situation is true?

The angular speed of a motor is 262 rad/s.The back emf generated by the motor is 89.4 V.Assuming all other factors remain the same,determine the back emf if the angular speed of the motor is reduced to 131 rad/s.

The current in the secondary coil of a step-up transformer is 1.25 A when the current in the primary coil is 0.30 A.Determine the turns ratio,N_s/N_p,of the transformer.

A single conducting loop with an area of 2.0 m² rotates in a uniform magnetic field so that the induced emf has a sinusoidal time dependence as shown. -What is the period of the induced current?

A 0.60-T magnetic field is directed perpendicular to the plane of a circular loop of radius 0.40 m.What is the magnitude of the magnetic flux through the loop?

A 0.100-m long solenoid has a radius of 0.050 m and 1.50 × 10⁴ turns.The current in the solenoid changes at a rate of 6.0 A/s.A conducting loop of radius 0.0200 m is placed at the center of the solenoid with its axis the same as that of the solenoid as shown. -What is the magnetic flux through the small loop when the current through the solenoid is 2.50 A?

A magnetic field is directed perpendicular to the plane of a 0.15-m × 0.30-m rectangular coil consisting of 240 loops of wire.To induce an average emf of -2.5 V in the coil,the magnetic field is increased from 0.1 T to 1.8 T during a time interval .Determine 11ec9dfc_0dce_3569_8d20_e155a830e031_TB6393_11.

Determine the energy stored in a 7.09 × 10^-⁷ H inductor that carries a 1.50-A current.

The figure shows a uniform magnetic field that is normal to the plane of the conducting loop of resistance R.Note: the area of the non-circular portion of the circuit is negligible compared to that of the loop. -Suppose that the radius of the loop is 0.500 m.At what rate must B change with time if the emf induced in the loop is 3p volts?

The figure shows a circular,conducting loop that is connected to a 5.0-V battery and a switch S.Immediately after the switch S is closed,the current through the loop changes at a rate of 15 A/s and the emf induced in the loop has a magnitude of 5.0 V.Determine the self-inductance of the coil.

A coil of wire with a resistance of 0.45 has a self-inductance of 0.083 H.If a 6.0-V battery is connected across the ends of the coil and the current in the circuit reaches an equilibrium value,what is the stored energy in the inductor?

A loop is pulled with a force F to the right to maintain a constant speed of 8.0 m/s.The loop has a length of 0.15 m,a width of 0.080 m,and a resistance of 200.0 .At the instant shown,the loop is partially in and partially out of a uniform magnetic field that is directed into the paper.The magnitude of the field is 1.2 T. -What is the magnitude of the emf induced in the loop?