![A 300 V, 5A, 0.2 pf low power factor wattmeter is used to measure the power consumed by a load](https://www.gkseries.com/blog/wp-content/uploads/2023/10/A-300-V-5A-0.2-pf-low-power-factor-wattmeter-is-used-to-measure-the-power-consumed-by-a-load.jpg)
Q. A 300 V, 5A, 0.2 pf low power factor wattmeter is used to measure the power consumed by a load. The wattmeter scale has 150 divisions and the pointer is on the 100th division. The power consumed by the load (in Watts) is .
Ans: 200
Sol:
Given that, voltage (V) = 300 V current (I) = 5A power factor (cos ϕ) = 0.2 Full scale reading of wattmeter, P = VI cos ϕ = 300 × 5 × 0.2 = 300 W Wattmeter scale has 150 divisions.
Each division constitutes,
![](https://www.gkseries.com/blog/wp-content/uploads/2023/10/image-23.png)
of reading.
While measuring the power consumed by a load, pointer is on the 100th division, 100 divisions constitute 100 × 2 = 200 W of power.