Question

a bulb of 100W operates for 6 hours a day . find the unit of energy consumed in 7 days.

Answer 1

Given:
P=100W
T per day =6 hrs

To find:
power consumption of bulb in 7 days

Soln:

Power consumed by bulb in 1 day=100×6
=600 W hrs

SINCE,1W hrs = 1000Kwh

Power consumed by bulb in 1 day=600÷1000kWh
=3/5 kWh

Therefore,power consumed by bulb in 7 days
=3/5×7
=21÷5
=4.2kWh