Question

Two
bulbs of 40 W each are light for
8 hour daily find the cost
of electrical energy consumed
by them in one week at rupees 3
per unit​

Answer 1

power of bulb=40 W

1000 W=1 kW

1 W=1/1000 kW

40 W=40/1000 kW

=1/25 kW

total energy=(1/25)*8

=8/25 kW hour

cost rate=3 rupees per unit

so,

cost=3*8/25

=24/25 rupees

=0.96 rupees

=96 paise