A non-conducting ring having a uniformly distributed negative charge is placed in the plane of smooth paper. A uniformly decreasing inward magnetic field is passing through the ring. Then,

1. Ring will start rotating anticlockwise.

2. Ring will start rotating clockwise.

3. Ring will jump and becomes floating above the paper.

4. No change will be observed in the position of the ring.

A motor having an armature resistance 2$\Omega$ is operating at 220 volts. At full speed, the back emf of the motor is 200 volts. Then the value of current in the armature at full speed is

1. 100 A

2. 10 A

3. 110 A

4. 0.55 A

The current I in an inductance coil varies with time t according to the graph shown in the figure. Which one of the following plots shows the variation of voltage in the coil with time?

1.		2.
3.		4.

A square loop enters into a uniform magnetic field. The sides of the square are 5 cm and its speed is 1 cm/s. Its front edge enters into the magnetic field at t=0, then which curve represents the variation of induced emf V?

1.             2. 

3.             4. 

The figure shows a current-carrying wire whose current is increasing continuously, then the direction of induced current in the conducting loop placed in the plane of paper is?

1. Anticlockwise

2. Clockwise

3. Zero

4. First clockwise then anticlockwise

Work done in increasing the current through a solenoid from 0 to 2 A is 20 J. Work done in increasing the current from 4 A to 6 A is:

A wire of length 6 m is rotated about the axis passing through point C and parallel to the magnetic field lines with angular velocity 4 radian/second. If B = 0.5T, the potential difference across the ends of the wire is

1. 2 V

2. 6 V

3. 12 V

4. Zero

The current flowing in an inductor of inductance 2.0 H varies as i = 2 sin(40t + $\pi /3$), where i is in amperes and t is in seconds. The maximum value of the emf induced in the inductor is:

1. 320 V

2. 160 V

3. 80 V

4. 4 V

If a magnet is allowed to fall through a long conducting pipe, then the final acceleration of the magnet will be

1. = g

2. $>g$

3. Zero

4. $\ge g$

In a uniform magnetic field, a ring is rotating about its axis which is parallel to the magnetic field and the magnetic field is perpendicular to the plane of the ring. The induced electric field in the ring: