Question 311: Current Electricity

Question

A galvanometer with its coil resistance 25 $$\Omega $$ requires a current of 1 mA for its full deflection. In order to construct an ammeter to read upto a current of 2 A,  the approximate value of the shunt resistance should be :

Accepted Answer

Given,
I
g
= 1 ma
I $$-$$ I
g
= 2 A
R
g
= 25 $$\Omega $$
$$	herefore\,\,\,$$ I
g
R
g
= (I $$-$$ I
g
) S
$$ \Rightarrow $$ $$\,\,\,$$ S = $${{{{10}^{ - 3}} 	imes 25} \over 2}$$
$$ \Rightarrow $$ $$\,\,\,$$ S =  1.25 $$ 	imes $$ 10
$$-$$2
$$\Omega $$

Answer

$$2.5 	imes {10^{ - 3}}\,\Omega $$

Answer

$$1.25 	imes {10^{ - 2}}\Omega $$

Answer

$$1.25 	imes {10^{ - 3}}\Omega $$

Answer

$$2.5 	imes {10^{ - 2}}\Omega $$

Current Electricity

A galvanometer with its coil resistance 25 $\Omega $ requires a current of 1 mA for its full deflection. In order to construct an ammeter to read upto a current of 2 A, the approximate value of the shunt resistance should be :

Choose the correct answer: