A dynamometer-type wattmeter is used to measure the power consumed by…

Previous year question for Non-Conventional Energy Resources and Instrumentation.

Question

A dynamometer-type wattmeter is used to measure the power consumed by a single-phase inductive load.

The readings are as follows:

Voltage across the load = 230 V

Current through the load = 10 A

Power factor of the load = 0.75 lagging

Wattmeter has a 2.5% low reading error due to stray magnetic fields and friction

Wattmeter constant = 600 revolutions per kWh

Calculate:

a) The actual power consumed by the load.

b) The ideal wattmeter reading.

c) The wattmeter reading with the 2.5% error applied.

If the load runs for 5 hours, calculate the total energy consumed and the number of revolutions of the energy meter.