A current of 3A flowing in the primary coil is reduced to zero in 0.001s, the induced e.m.f. in the secondary is 15000 V. The mutual inductance between the two coils is
0.5 H
5 H
1.5 H
10 H
Two inductors each of inductance L are connected in parallel. What is their equivalent inductance?
A coil of resistance R and inductance L is connected to a battery of e.m.f. E volts. The final current in the coil is
If a current is passed through a spring, then the spring
expands
gets compressed
remains same
None of these
Two coils have a mutual inductance of 0.005 H. The current changes in the first coil according to the equation I = I0 sin ωt where I0 = 10A and ω = 100π rad/sec. The maximum value of e.m.f. in the second coil is
5π volts
2π volts
π volts
4π volts
What is the coefficient of mutual induction when the magetic flux changes by 2 x 10-2 Wb and change in current is 0.01A?
3 H
0. 5 H
2 H
zero
The inductance of a coil is directly proportional to
its length
the number of turns
the resistance of the coil
the square of the number of turns
A long solenoid has 200 turns/cm and carries a current I. The magnetic field at its centre is 5.28 x 10-2 Wbm-2. Another long solenoid has 100 turns/cm and it carries a current I/3. The value of the magnetic field at its centre is
1.05 x 10-2 Wb m-2
1.05 x 10-5 Wb m-2
1.05 x 10-3 Wb m-2
1.05 x 10-4 Wb m-2
A current varying at the rate of 3A/s in a coil generates an e.m.f. of 8mV in a nearby coil. The mutual inductance of the two coils is
2.66 H
2.66 x 10-3 mH
0.266 H
2.66 mH
A horizontal straight wire, 10m long, extending along the east and west direction, is falling at right angles to the horizontal component of the earth's magnetic field, 0.30 x 10-4 Wbm-2. If the induced emf is 1.5 x 10-3, the velocity of the wire is :
5 x10-4 ms-1
5 x 102 ms-1
50 ms-1
5 ms-1