Question

A rectangular coil of 400 turns on frame of 3cm x 2cm is suspended in magnetic field of induction
0.1 T. A current of 10 ? A flows through the coil. The torque on it in N-m is
[ ]
a) 2.4 x 10-5
b) 2.6 x 10-2
c) 2.4 x 109
d) 4.8 x 10
​

Answer 1

Answer:

c) 2.4 x 109

Explanation:

.......................

Answer 2

The torque on the rectangular coil due to presence of magnetic field is given,

τ=NIABsinθ

where number of turns N=500,

Current in the coil I=2A,

Area of the coil A=(10×5)10

−4

m

2

,

Magnetic field B=2×10

−3

T,

Angle between area and magnetic field vector is θ

As area vector is always normal to plane and given the plane is parallel to field, so the angle between area and field is 90

o

.

So, τ=500×2×(10×5)×10

−4

×(2×10

−3

)sin90=0.01Nm