For tangent galvanometer, Deflection, θ=30∘ Resistance of coil, R=9Ω Potential difference across coil, V=4.5V Number of turns in the coil N=10 BH=3.14×10−5T Current flowing through the coil, I=‌
V
R
=‌
4.5
9
=0.5A We know that, current flowing through the galvanometer is given as I=‌