Practice portal › Moving Charges and Magnetism › Moving Coil Galvanometer and its Conversion

The galvanometer has a resistance of 18 Ω. Calculate the value of shunt to increase the range of galvanometer by 10 times.

Asked in GUJCET 2023 · Conversion to ammeter and voltmeter

Answer: (4) 2 Ω

Step-by-step solution

Given: galvanometer resistance G=18 Ω; the range is to be multiplied by n=10.

Idea: a shunt in parallel carries the current the coil must not, and being in parallel the two have the same voltage across them.

At full scale the coil still takes I_g while the line carries I=nI_g, so the shunt carries (n-1)I_g.

Equal voltages: I_g G=(n-1)I_g S, so S=G/(n-1).

S=(18)/(10-1)=2 Ω.

Why the other options are wrong

More Moving Coil Galvanometer and its Conversion questionsAll Moving Coil Galvanometer and its Conversion questions →

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.

Practise this with a timer