Question

A rectangle is bent on two sides at 90° so that one end lies along the xy plane while the other end lies along the xz plane. The length a = 10 cm and b = 30 cm. A magnetic field of strength B = 0.1 T lies in the yz plane and points at an angle θ = 30° with the y axis. The flux through the rectangle is

A. 52.0 mWb
B.30.0 mWb
C.41.0 mWb
D.60.0 mWb
E.None of these is correct.

Answer 1

The correct option is (c) 41.0 mWb

Explanation:

Given:

Magnetic field, B = 0.1 T

Angle with y-axis, Θ = 30°

Length a = 10 cm

b = 30 cm

now since the plate is rectangular,

the area , A = a x b = 10 x 30 = 0.10 x 0.30 = 0.03 m2

now,

For X-Y plane :

The value for the flux is given as:

Flux = Bsin30° x Area = 0.1×(0.5)×0.03 = 15 mWb

Now, For X-Z plane :

Flux = BCos30° x Area = 0.1×(0.87)×0.03 = 26.1 mWb

Therefore,the total flux will be = 15 mWb + 26.1 mWb = 41.1 mWb ≈ 41 mWb

hence, the correct option is (c) 41.0 mWb