Question

Resistance of galvanometer	Shunt resistance
A) 200 $\Omega$	a) 50 $\Omega$
B) 100 $\Omega$	b) 20 $\Omega$
C) 300 $\Omega$	c) 50 $\Omega$

The increasing order of sensitivity of ammeter is

• A. A, B, C
• B. A, C, B
• C. C, B, A
• D. C, A, B

Answer 1

Answer: (D)

C, A, B

the low resistance shunt is always connected in parallel to galvanometer.

$\therefore R_{eqv}=\frac{RG}{R+G}$

A) $R_{eqv}=\frac{50\times 200}{250}=40\Omega$

B) $R_{eqv}=\frac{100\times 20}{120}=16.67\Omega$

C) $R_{eqv}=\frac{300\times 50}{350}=42.86\Omega$

Sensitivity of ammeter is inversely proportional to resistance.

So, order of sensitivity is
$C<A<B$