A rectangular coil of 10 turns, each of area 0.05 m2 , is suspended fr

1.	A rectangular coil of 10 turns, each of area 0.05 m2 , is suspended freely in a radial magnetic field of 0.01 Wb/m2. If the torsional constant of the suspension fibre is 5 × 10-9 N∙m per degree, find the angle through which the coil rotates when a current of 30 μA is passed through it.
Answer» Data : A = 0.05 m², B = 0.01 Wb/m², N = 10, C = 5 × 10^-9 N∙m per degree, I = 30 μA = 30 × 10 A, I = \(\left(\cfrac{C}{NAB}\right)\) θ ∴ The deflection of the coil, θ = \(\cfrac{NIAB}C\) = \(\cfrac{10\times30\times10^{-6}\times0.05\times0.01}{5\times10^{-9}}\) = 30°

A rectangular coil of 10 turns, each of area 0.05 m2 , is suspended freely in a radial magnetic field of 0.01 Wb/m2. If the torsional constant of the suspension fibre is 5 × 10-9 N∙m per degree, find the angle through which the coil rotates when a current of 30 μA is passed through it.

Answer»

Data : A = 0.05 m²,

B = 0.01 Wb/m²,

N = 10, C

= 5 × 10^-9 N∙m per degree,

I = 30 μA = 30 × 10 A,

I = \(\left(\cfrac{C}{NAB}\right)\) θ

∴ The deflection of the coil,

θ = \(\cfrac{NIAB}C\) = \(\cfrac{10\times30\times10^{-6}\times0.05\times0.01}{5\times10^{-9}}\) = 30°