Question

In an ammeter 4% of the main current is passing through galvanometer. If the galvanometer is shunted with a 3 ohm resistance

Answer 1

Answer:

Shunt is a low resistance connected in parallel with the galvanometer or ammeter.

If the current flowing in a circuit is strong, a galvanometer or an ammeter cannot be put directly in it because the instrument may be damaged. To overcome this difficulty, a low resistance (ie, shunt) is connected in parallel with this instrument. Then a major portion of the current passes through this low resistance (ie, shunt) and only a small portion passes through the instrument. Due to it, the galvanometer or an ammeter remains safe.

Shunt is given by

S=  IgG/I - I g

∴ 5=  4/100 IG / I - 4/100y = 4G/96

or G= 96 × 5 / 4

=120Ω

Explanation: