Question

A  DC ammeter is rated for 15 A, 250 V. The meter constant is 14.4 A-s/rev. The meter constant at rated voltage may be expressed as __________

(a) 3750 rev/kW-h

(b) 3600 rev/kW-h

(c) 1000 rev/kW-h

(d) 960 rev/kW-h

The question was posed to me in a national level competition.

This is a very interesting question from Advanced Miscellaneous Problems on Measurement of Resistance in chapter Measurement of Resistance of Electrical Measurements

Answer 1

Correct option is (c) 1000 rev/kW-h

The best explanation: Meter constant is 14.1 A-s/rev

\(\frac{14.1}{3600}\) A-h/rev = \(\frac{14.4 × 250}{3600}\)

So, w = 1 W-h/rev

Hence, 1 rev/W-h = 1000 rev/kW-h.