JEE Main202227 Jun 2022Morning ShiftPhysicsCurrent ElectricityActual
A 72 Ω galvanometer is shunted by a resistance of 8 Ω . The percentage of the total current which passes through the galvanometer is
Options
- A0 . 1 %
- B10 %
- C25 %
- D0 . 25 %
Correct answer
B. 10 %
Step-by-step solution
Let G be resistance of galvanometer and I ' be the current passing through the galvanometer produces full scale deflection. If I is the maximum current, and since, G and S are in parallel so, the potential difference between them will be same. Then, I ' G = I 2 S ⇒ 72 I ' = 8 I 2 ⇒ I 2 = 9 I ' ⇒ I = I ' + I 2 = 10 I ' So the percentage of total current passes through galvanometer is I ' I × 100 = I ' 10 I ' × 100 = 10 %