An aircraft has a wing span of 35 m. It is flying horizontally with a speed of 9.ms-1 and the vertical component of earth's magnetic field is 4 x 10-5T. The potential difference between the tips of the wings will be
12.6 V
0.126 V
1.26 V
0.013 V
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
Two circuits have mutual inductance of 0.09 H. Average e.m.f. induced in the secondary by a change of current from 0 to 20 A in 0.006 second in the primary will be
300 V
200 V
180 V
120 V
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
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
The north pole of a long horizontal bar magnet is being brought closer to vertical conducting plane along the perpendicular direction. The induced current in the conducting plane is :
anticlockwise
clockwise
horizontal
vertical
What is the coefficient of mutual induction when the magetic flux changes by 2 x 10-2 Wb and corresponding change in current is 0.01A ?
3 H
0.5 H
2 H
When the current changes from +2 A to -2 A in 0.05 seconds an emf of 8V is induced in the coil. The coefficient of self-induction of the coil is :
0.2H
0.4H
0.8H
0.1H
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
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