Question

Meter A has a range of 0 – 100 V and a multiplier resistance of 28 kΩ and an internal resistance of 2 kΩ. It’s sensitivity is:
1. 0.6 kΩ/kV
2. 0.3 kΩ/V
3. 0.5 kΩ/V
4. 3 kΩ/V

Answer 1

Correct Answer - Option 2 : 0.3 kΩ/V

Concept:

Total internal resistance of a voltmeter is given by

\({R_m} = \frac{{{V_{fsd}}}}{{{I_{fsd}}}}\)

Sensitivity (S) of a voltmeter is the reciprocal of full-scale deflection current (Ifsd)

Rm = full scale range of voltmeter × sensitivity

Rv = Vfsd × S

Calculation:

Given that, full scale range of voltmeter (Vfsd) = 100 V

Internal resistance (Rm) = 2 kΩ

Multiplier resistance = 28 kΩ

Total resistance = 30 kΩ

Sensitivity (S) = 30/100 kΩ/V = 0.3 kΩ/V