Magnetic Effects Of Current Question 2
Question 2 - 2024 (01 Feb Shift 2)
A moving coil galvanometer has 100 turns and each turn has an area of $2.0 cm^{2}$. The magnetic field produced by the magnet is $0.01 T$ and the deflection in the coil is 0.05 radian when a current of $10 mA$ is passed through it. The torsional constant of the suspension wire is $x \times 10^{-5} N-m / rad$. The value of $x$ is
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Answer: (4)
Solution:
$\tau=$ BINAsin
$C \theta=$ BINAsin $90^{\circ}$
$C=\frac{\text { BINA }}{\theta}=\frac{0.01 \times 10 \times 10^{-3} \times 100 \times 2 \times 10^{-4}}{0.05}$
$=4 \times 10^{-5} N-m / rad$.
$x=4$