# A rectangular loop of area

A rectangular loop of area 20 cm x 30 cm is placed in magnetic field of 0.3 T with its plane
(i) normal to the field
(ii) inclined 30° to the field and
(iii) parallel to the field.
Find the flux linked with the coil in each case.

Here A = 20cm x 30 cm = 6 x ${{10}^{-2}}$${{m}^{2}}$
B = 0.3 T
Let θ be the angle mady by the field B with the normal to the plane of the coil.
(i) Here, θ = 90°- 90° = 0°
so,flux, $\phi$ = BA Cos θ
$\phi$ = 0.3 x 6 x ${{10}^{-2}}$ x cos0°
= 1.8 x ${{10}^{-2}}$ Wb
(ii) Here, θ = 90° - 30° = 60°
$\phi$ = 0.3 X 6 X ${{10}^{-2}}$ x cos 60°
$\phi$ = 0.9 x ${{10}^{-2}}$ Wb
(iii) Here, θ = 90°
$\phi$ = 0.3 X 6 X ${{10}^{-2}}$ x cos90°
$\phi$ = θ