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(a) Define the current sensitivity of a galvonometer . (b) The coil area of a galvonometer is 16 xx 10^(-4) m^(2). It consists of 200 turns of wire and is in a magnetic field of 0.2 T. The restoring torque constant of the suspended fibre is 10^(-6) N m per degree . Assuming the magnetic field to be radial, calculate the maximum current that can be measured by the galvanometer if the scale can acomodate 30^@ deflection. |
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Answer» SOLUTION :(b) Here area `A = 16 xx 10^(-4) m^(2)`, no. of turns `N = 200`, magnetic field B = 0.2 T, torque constant `k = 10^(-6) N - m` PER DEGREE and maximum DEFLECTION `phi = 30^@`. Hence, maximum current that can be `I = k/(N A B) phi= (10^(-6) xx 30)/(200 xx (16 xx 10^(-4)) xx 0.2) = 4.7 xx 10^(-4) "or" 0.47 mA`. |
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