Discussion Forum



1)

 In conversion of moving coil  galvanometer into an ammeter of required range, the resistance of ammeter , so formed is       

[ S= shunt and G= resistance of galvanometer]


A) $\frac{S+G}{SG}$

B) $\frac{SG}{S+G}$

C) $\frac{S-G}{SG}$

D) $\frac{SG}{S-G}$

Answer:

Option B

Explanation:

 A moving coil galvanometer can be converted into an ammeter by connecting a low resistance (called shunt resistance) in parallel to it.

 Hence, the resistance  (R) of the ammeter , so formed is 

$\frac{1}{R}=\frac{1}{S}+\frac{1}{G}$

$R=\frac{SG}{S+G}$