CBSE
Multiple Choice QuestionsIf a current of 3 A fl.owing in the primary coil is reduced to zero in 0.01 s then the induced emf in the secondary coil is 1500 V, the mutual inductance between the two coils is :
0.5 H
5 H
1.5 H
10 H
Two similar coils are kept mutually perpendicular such that their centres coincide. At the centre, find the ratio of the magnetic field due to one coil and the resultant magnetic field through both coils, if the same current is flown :
1 :
1 : 2
2 : 1
: 1
Lenz's law is based on the principle of conservation of
mass
charge
momentum
energy
A conducting square loop of side L and resistance R moves in its plane with a uniform velocity v, perpendicular to one of its sides. A magnetic field of induction B, constant in space and time and pointing perpendicularly into the plane of the square, exists everywhere in space. The current induced in the loop is
BLv/R in the clockwise direction
BLv/R in the anticlockwise direction
2 BLv/R in the clockwise direction
zero
Two coils are placed close to each other. The mutual inductance of the pair of coils depends upon
the rates at which currents are changing in the two coils
relative position and orientation of the two coils
the materials of the wires of the coils
the currents in the two coils
A circular coil has 500 turn of wire and its radius is 5 cm. The self inductance of the coil is
25 x 10-3 mH
25 mH
50 x 10-3 H
50 x 10-3 mH
The unit of inductance is
1 Wb/m2 is equal to
104 G
102 G
10-2 G
10-4 G
A steady current of 5 A is maintained for 45 min. During this time it deposits 4.572 g of zinc at the cathode of a voltmeter. ECE of zinc is
3.38 × 10-4 g/C
3.397 × 10-4 g/C
3.384 × 10-3 g/C
3.394 × 10-3 g/C
A magnetising field of 1600 A/m produces a magnetic flux 2.4 x10-5 Wb in an iron bar of cross-sectional area 0.2 cm2. The susceptibility of an iron bar will be
1788
1192
596
298
