Question

A galvanometer has a coil with a resistance of 24.0 Ω, and a current of 180 μA causes it to deflect full scale. If this galvanometer is to be used to construct an ammeter that can read up to 10.0 A, what shunt resistor is required? A galvanometer has a coil with a resistance of 24.0 , and a current of 180 μA causes it to deflect full scale. If this galvanometer is to be used to construct an ammeter that can read up to 10.0 A, what shunt resistor is required? 234 µΩ 123 µΩ 342 µΩ 423 µΩ 432 µΩ

Answer 1

Answer:

shunt resistor is 432µΩ

correct option is  432µΩ

Explanation:

given data

resistance R = 24.0 Ω

full scale deflection current Ig = 180 μA

galvanometer current I = 10.0 A

to find out

what shunt resistor is required

solution

we will apply here full scale deflection current  formula that is

Ig = I × $\frac{r}{r + R}$    ...............1

here r is shunt current and R is resistance and I is galvanometer

put here all value

180 × $10^{-6}$ = 10 × $\frac{r}{r + 24}$

r = 18 ×  $10^{-6}$  × 24

r = 432 ×  $10^{-6}$ Ω

so shunt resistor is 432µΩ

correct option is  432µΩ