Question

the resistance of a moving coil galvanometer is 20ohm . it require 0.01A current for full scale deflection. Calculate the value of resistance require d to convert it into a voltmeter of range 20volts.​

Answer 1

Explanation:

G=20Ω I

g

=50×10

−3

A;I=20A,

S=?;V=120V,R=?

Solution:

i) ∴S=G.

I−I

g

I

g

=

20−50×10

−3

20×50×10

−3

=

20−0.05

1

S=0.05Ω

A shunt of 0.05Ω should be connected in parallel.

ii) R=

Ig

V

−G

=

50×10

−3

120

−20=2400−20=2380Ω

R=2380Ω.