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
Both (a ) and ( b ) are correct
None of the above
A straight wire of diameter 0.5 mm carrying a current of 1 A is replaced by another wire of 1 mm diameter carrying same current. The strength of magnetic field far away is
twice the earlier value
same as the earlier value
one – half of the earlier value
one quarter of the earlier value
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 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
Tesla is the unit of
magnetic flux
magnetic field
magnetic induction
magnetic moment
Two equal electric currents are flowing perpendicular to each other as shown in the figure. AB and CD are perpendicular to each other and symmetrically placed with respect to the currents, where do we expect the resultant magnetic field to be zero?
On AB
On CD
On both AB and CD
On both OD and BO
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 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
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
