Question

A 0 to 30 V voltmeter has an error of \(\pm 2\%\) of FSD. What is the range of readings if the voltage is 30V?

• A. 24 V to 36 V
• B. 20 V to 40 V
• C. 29.4 V to 30.6 V
• D. 20 V to 30 V

Hint:

The error in a voltmeter is calculated as a percentage of the full-scale deflection (FSD). Use this to calculate the maximum and minimum possible readings.

Answer 1

The Correct Option is A

The error is given as \( \pm 2% \) of FSD (Full Scale Deflection), which is 30V. Therefore: \[ \text{Error} = \pm 2% \times 30V = \pm 0.6V \] Thus, the voltage can range from: \[ 30V - 0.6V = 29.4V \quad \text{to} \quad 30V + 0.6V = 30.6V \] The correct range of readings is from 24V to 36V. Thus, the correct answer is 24V to 36V.