A current of 3 A flowing in the primary coil is reduced to zero in 0.001 s, 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
A positively charged particle moving due east enters a region of uniform magnetic field directed vertically upwards. The particle will
continue to move due east
move in a circular orbit with its speed unchanged
move in a circular orbit with its speed increased
gets deflected vertically upwards
A circuit has a self inductance of 1 H and carries a current of 2 A. To prevent sparking when the circuit is broken, a capacitor which can withstand 400 V is used. The capacitance of the capacitor is
25 μF
125 μF
100 pF
50 μF
A current carrying coil is subjected to a uniform magnetic field. The coil will orient so that its plane becomes
inclined at 45o to the magnetic field
inclined at any arbitrary angle to the magnetic field
parallel to the magnetic field
perpendicular to magnetic field
A magnetic field of 2 x 10-2 T acts at right angles to a coil of area 100 cm2 with 50 turns. The average e.m.f. induced in the coil is 0.1 V when it is removed from the field in t sec. The value of t is
0.1 s
10 s
0.01 s
1s
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
During a current change from 2 A to 4 A in 0.05 second, 8 V of e.m.f. is developed in the coil. The coefficient of self induction is
0.1 H
0.4 H
0.8 H
0.2 H
A coil has an area of 0.05 m2 and has 800 turns. After placing the coil in a magnetic field of strength 4 x 10-5 Wbm-2, perpendicular to the field, the coil is rotated by 90o in 0.1s.The average emf induced is
zero
0.016 V
0.01 V
0.032 V
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
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
