If 2 % of the main current is to be passed through the galvanometer of resistance G, the resistance of the shunt required is :

Question

If 2 % of the main current is to be passed through the galvanometer of resistance G, the resistance of the shunt required is : (A)  (G/49)  (B)  (G/50)  (C) 49 G (D) 50 G

Tardigrade Admin · Accepted Answer

The potential difference across parallel combination should be equal.
The shunt is a low resistance connected in parallel with the galvanometer as shown. Potential difference across

G

=

potential difference across

S .

i. e.

i_{g} G = (i - i_{g}) S

or

i_{g} G + i_{g} S = i S

or

i_{g} (G + S) = i S

or

\frac{i _{g}}{i} = \frac{S}{S + G}

Given,

\frac{i _{g}}{i} = \frac{2}{100}

we have

\frac{2}{100} = \frac{S}{S + G}

or

2 S + 2 G = 100 S

or

G = \frac{98 S}{2}

or

S = \frac{G}{49}

Q. If $2%$ of the main current is to be passed through the galvanometer of resistance $G$ , the resistance of the shunt required is :

$\frac{G}{49}$

$\frac{G}{50}$

$49 G$

$50 G$

Q. If 2% of the main current is to be passed through the galvanometer of resistance G, the resistance of the shunt required is :

49G​

50G​

49G

50G

Q. If $2%$ of the main current is to be passed through the galvanometer of resistance $G$ , the resistance of the shunt required is :

$\frac{G}{49}$

$\frac{G}{50}$

$49 G$

$50 G$