A voltmeter consists of a 25 Ω coil in series with a 575 Ω resistor. The coil requires 10 mA for full-scale deflection. Find the maximum potential difference (V) this voltmeter can measure.
Physics · Mixed Chapter
JEE Mains

Question

A voltmeter consists of a 25 Ω coil in series with a 575 Ω resistor. The coil requires 10 mA for full-scale deflection. Find the maximum potential difference (V) this voltmeter can measure.

G1 Physics · Accepted Answer

Step 1 — Determine total series resistance: Voltmeter coil resistance = 25 Ω; series multiplier resistance = 575 Ω. R = 25 + 575 = 600 Ω. Step 2 — Full-scale voltage: The coil carries its maximum permissible current at full scale: I = 10 mA = 0.010 A. Vₘₐₓ = IR = 0.010×600 = 6 V. Answer: 6.