Question

Find the electric energy consumed by an electric bulb operated at 5A, 220V for 4 hrs.​

Answer 1

Answer:

Power P=50W Rated voltage V=220V Time t=20minutes. Energy consumed E=P×t. Commercial unit of electrical energy is kWh.

Explanation:

Answer 2

Answer:

The electrical energy consumed by the bulb is 4.4 kWh.

Explanation:

The current through the bulb, I = 5 A

The voltage across the bulb, V = 220 V

The time of flow of the current, t = 4 Hr

The power of the bulb, P = I × V

                                          = 5 × 220

                                          = 1100 W

The electrical energy consumed is expressed in kWh. So the power should be in kW and time should be in hrs.

∴ Power of the bulb, P = 1100 W = 1100/1000 kWh = 1.1 kWh

The electrical energy consumed by the bulb, E = P × t

                                                                               = 1.1 × 4

                                                                               = 4.4 kWh