The magnetic field in a coil of 100 turns and 40 square cm area is increased from 1 Tesla to 6 Tesla in 2 second. The magnetic field is perpendicular to the coil. The e.m.f. generated in it is 

1. 10⁴ V

2. 1.2 V

3. 1.0 V

4. 10^–2 V

A metallic ring connected to a rod oscillates freely like a pendulum. If now a magnetic field is applied in the horizontal direction so that the pendulum now swings through the field, the pendulum will

1. Keep oscillating with the old-time period

2. Keep oscillating with a smaller time period

3. Keep oscillating with a larger time period

4. Come to rest very soon

In a circuit with a coil of resistance \(2~\Omega,\) the magnetic flux changes from \(2.0\) Wb to \(10.0\) Wb in \(0.2\) s. The charge that flows in the coil during this time is:
1. \(5~\text{C}\)
2. \(4~\text{C}\)
3. \(1~\text{C}\)
4. \(0.8~\text{C}\)

The total charge induced in a conducting loop when it is moved in the magnetic field depends on 

1. The rate of change of magnetic flux

2. Initial magnetic flux only

3. The total change in magnetic flux

4. Final magnetic flux only

An aluminum ring B faces an electromagnet A. The current I through A can be altered. Then :

1. Whether I increases or decreases, B will not experience any force

2. If I decrease, A will repel B

3. If I increases, A will attract B

4. If I increases, A will repel B

A coil having \(n\) turns and resistance \(R~\Omega\) is connected with a galvanometer of resistance \(4R~\Omega\). This combination is moved in time \(t\) seconds from a magnetic field \(W_1\) weber/m² to \(W_2\) weber/m². The induced current in the circuit is:
(Assume area = \(1\) m²)

A rectangular coil ABCD is rotated anticlockwise with a uniform angular velocity about the axis shown in the diagram below. The axis of rotation of the coil as well as the magnetic field B are horizontal. The induced e.m.f. in the coil would be maximum when 

1. The plane of the coil is horizontal

2. The plane of the coil makes an angle of 45° with the magnetic field

3. The plane of the coil is at right angles to the magnetic field

4. The plane of the coil makes an angle of 30° with the magnetic field

An electric potential difference will be induced between the ends of the conductor shown in the diagram when the conductor moves in the direction 

1. P

2. Q

3. L

4. M

Two rails of a railway track insulated from each other and the ground are connected to a milli voltmeter. What is the reading of voltmeter, when a train travels with a speed of \(180\) km/hr along the track.
(Given that the vertical component of earth's magnetic field is \(0.2\times 10^{-4}\) weber/m² and the rails are separated by \(1\) m) 
1. \(10^{-2}\) V
2. \(10^{-4}\) V
3. \(10^{-3}\) V
4. \(1\) V

A conducting square loop of side \(L\) and resistance \(R\) moves in its plane with a uniform velocity \(v\) perpendicular to one of its sides. A magnetic induction \(B\) constant in time and space, pointing perpendicular and into the plane of the loop exists everywhere. The current induced in the loop is: