Question

A galvanometer has a resistance of 100ohm. A difference of potential of 1V between its terminals gives a full scale deflection. Calculate the shunt resistance which will enable the instrument to read upto 2A.​

Answer 1

Answer:

A shunt resistance (S) need to be connected to galvanometer in

parallel to convert into ammeter.

galvanometer resistance = 100

I(g) = 20 A

1 A for 100 th division.

So for 50 divisions it will be 100 A.

So we need to make ammeter of 0 - 100 A

I = 100 A

S = I(g)×G/(I−I(g))

S = 20×100/(100−20)

S = 200/80

S = 2.5 Ohm

Answer 2

answer

The current required for full-scale deflection is

The shunt resistance required is