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:

Which of the following is not based on the application of eddy currents?

1. Speedometer

2. Dead-beat galvanometer

3. Energy meter

4. Tangent galvanometer

A railway track running north-south has two parallel rails l distance apart. If H is the horizontal component of the earth's field, angle of dip is $\theta$, then the induced emf between the rails when a train passes with velocity v, is

1. Hlvtan$\theta$

2. Hlv

3. Hlvcos$\theta$

4. Hlvsin$\theta$

Two coils of self-inductance L₁ and L₂ are placed so close together that they completely link the magnetic flux of each other. If M be their mutual inductance then, the correct relation is 

1. M = $\sqrt{\frac{L_1}{L_2}}$

2. M = L₁$\sqrt{L_2}$

3. M = L₁L₂

4. M = $\sqrt{L_1{L}_2}$