Question

A TG has 500 turns , each of radius $2\pi cm$ . If $B_H=3.6\times 10^{-5}Wb/m^2$ , The deflection due to 7.2 mA current is .

• A. $60^{\circ }$
• B. $30^{\circ }$
• C. $45^{\circ }$
• D. Zero

Answer 1

Answer: (C)

for tangent galvanometer
$B_H\tan \theta =\frac{n{\mu }_{0}i}{2r}$
$3.6\times 10^{-5}\times \tan \theta =\frac{500\times 4\pi \times 10^{-7}\times 7.2\times 10^{-3}}{2\times 2\pi \times 10^{-2}}$
$\tan \theta =1$
$\theta =45^0$