Electromagnetic Induction

A uniform magnetic field of 0.4 T acts perpendicular to a circular copper disc 20 cm in radius. The disc is having a uniform angular velocity of 10 rad s-1 about an axis through its centre and perpendicular to the disc. What is the potential difference developed between the axis of the disc and the rim? ( = 3.14)

1. 0.5024 V
2. 0.0628 V
3. 0.2512 V
4. 0.1256 V

[figure] A conducting bar moves on two conducting rails as shown in the figure. A constant magnetic field B exists into the page. The bar starts to move from the vertex at time t = 0 with a constant velocity. If the induced EMF is E tn, then value of n is .

Regarding self-inductance: Choose the correct answer from the options given below:

1. A, B, C, E only
2. A, B, C, D only
3. A, C, D, E only
4. B, C, D, E only

[figure] In the given circuit the sliding contact is pulled outwards such that electric current in the circuit changes at the rate of 8 A/s. At an instant when R is 12 , the value of the current in the circuit will be A.

A rectangular metallic loop is moving out of a uniform magnetic field region to a field free region with a constant speed. When the loop is partially inside the magnetic field, the plot of magnitude of induced emf ( ) with time (t) is given by

1. [figure]
2. [figure]
3. [figure]
4. [figure]