A galvanometer of resistance 20Ω shows a deflection of 10 divisions. When current of 1 mA is passed through it. If a shunt of 4Ω is connected and there are 50 divisions on the scale, the range of the galvanometer is

Question

A galvanometer of resistance 20Ω shows a deflection of 10 divisions. When current of 1 mA is passed through it. If a shunt of 4Ω is connected and there are 50 divisions on the scale, the range of the galvanometer is (A) 35 mA (B) 40 mA (C) 30 mA (D) 25 mA

Tardigrade Admin · Accepted Answer

Here, galvanometer current ig=(1mA/10)× 50=5mA S=4Ω and G=20Ω As, sheet S=(igG/i-ig)⇒ 4=(5× 10-3× 20/i-2× 10-3) On solving, we get i=30× 10-3=30mA

Q. A galvanometer of resistance $20Ω$ shows a deflection of 10 divisions. When current of 1 mA is passed through it. If a shunt of $4Ω$ is connected and there are 50 divisions on the scale, the range of the galvanometer is

35 mA

40 mA

30 mA

25 mA

Here, galvanometer current $i_{g} = \frac{1 m A}{10} \times 50 = 5 m A$ $S = 4Ω$ and $G = 20Ω$ As, sheet $S = \frac{i _{g} G}{i - i _{g}} \Rightarrow 4 = \frac{5 \times 10 ^{- 3} \times 20}{i - 2 \times 10 ^{- 3}}$ On solving, we get $i = 30 \times 10^{- 3} = 30 m A$

Q. A galvanometer of resistance 20Ω shows a deflection of 10 divisions. When current of 1 mA is passed through it. If a shunt of 4Ω is connected and there are 50 divisions on the scale, the range of the galvanometer is