Q. A circuit contains an ammeter, a battery of 30 V and a resistance 40.8 ohm all connected in series. If the ammeter has a coil of resistance 480 ohm and a shunt of 20 ohm, the reading in the ammeter will be :
A) 1 A
B) 0.5 A
C) 0.25 A
D) 2 A
Explanation
[Solution] Ammeter resistance = $\frac{480 \times 20}{500} = 19.2$ Ω; I = 30/(40.8 + 19.2) = 0.5 A. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.