Magnetic field due to 0.1 A current flowing through a circular coil of radius 0.1m and 1000 turns at the centre of the coil is
0.2 T
2 × 10-4 T
6.28 × 10-4 T
9.8 × 10-4 T
A straight wire of length 0.5 m and carrying a current of 1.2 A is placed in uniform magnetic field of induction 2 T. The magnetic field is perpendicular to the length of the wire. The force on the wire is
2. 4 N
1.2 N
3.0 N
2.0 N
The total charge induced in a conducting loop when it is moved in magnetic field depends on
the rate of change of magnetic flux
initial magnetic flux only
the total change in magnetic flux
final magnetic flux only
Current is flowing in a coil of area A and number of turns N, then magnetic moment of the coil, M is equal to
NiA
Ni/A
N2Ai
The magnetic field at a distance r from a long wire carrying current I is 0.4 T. The magnetic field at a distance 2r is
0.8 T
0.1 T
1.6 T
A deutron of kinetic energy 50 keV is describing a circular orbit of radius 0.5 m in a plane perpendicular to magnetic field B. The kinetic energy of the proton that describes a circular orbit of radius 0.5 m in the same plane with the same B is
25 keV
50 keV
200 keV
100 keV
A coil of one turn is made of a wire of certain length and then from the same length a coil of two turns is made. If the same current is passed is both the cases, then the ratio of the magnetic induction at their centers will be
2 : 1
1 : 4
4 : 1
1 : 2
torque is formed
emf is induced
Both (a ) and ( b ) are correct
None of the above
A galvanometer of resistance 50 Ω is connected to a battery of 3 V along with a resistance of 2950 Ω in series. A full scale deflection of 30 divisions is obtained in the galvanometer. In order to reduce this deflection to 20 divisions, the resistance in series should be
5050 Ω
5550 Ω
6050 Ω
4450 Ω
At what distance from a long straight wire carrying a current of 12 A will the magnetic field be equal to 3 x 10-5 Wb/m2?
8 × 10-2 m
12 × 10-2 m
18 × 10-2 m
24 × 10-2 m
