Electromagnetic Induction NAT Level - 1 - Physics MCQ

When current flowing in a coil changes from 3A to 2A in the millisecond, 5 volt emf is induced in it. The self-inductance of the coil (in mH) will be :

The magnetic flux linked with the coil varies with time as  φ = 3t² + 4t + 9. The magnitude of induced emf (in Volts) at  t = 2 second is.

The spokes of a wheel are made of metal and their lengths are of one metre. One rotating the wheel about its own axis in a uniform magnetic field of 5 × 10^–6 tesla  normal to the plane of the wheel a potential difference of 3.14 mV  is generated between the rim and the axis. The rotational velocity  of the wheel is (in  rev/sec).

If in a coil rate of change of area is 5m²/ms  and current becomes 1 Amp from 2 Amp in 2×10^–3sec. If magnetic field is 1 tesla  then self inductance (in Henry) of the coil is :

When the primary current in the spark coil of a car changes from 4A to zero in 10µs, an emf of 40,000V  is induced in the secondary. The mutual inductance (in  Henry) between the primary and the secondary windings of the spark coil will be.

A metallic rod completes its circuit as shown in the figure. The circuit is normal to a magnetic field  B = 0.15 tesla. If the resistances of the rod is 3Ω the force required to move the rod with a constant velocity of 2 m/sec is    Find the value of  α.

Area of a coil is 0.16 m². If magnetic field through it changes from 0.1 Wb/m² to 0.5 Wb/m²  in  0.02 s, then the emf induced (in Volts) in the coil will be.