Question

An electric refrigerator rated 600 W operates for 8 hours/day . What is the energy consumed by it in one day in kilowatt-hours ?
10 points
a. 4800 kWh
b. 750 kWh
c. 4.8 kWh
d. 75 kWh​

Answer 1

ANSWER

Energy of one day =Power×Time=400W×8h=3.2KWh

Energy of 30 days =3.2KWh×30=96KWh

So, cost of the energy =96×3=Rs.288

Answer 2

Given:-

→ Power of the refrigerator = 600 W

→ Time for which it is operated /day = 8h

To find:-

→ Energy consumed by the refrigerator in

one day [ in kilowatt-hours ]

Solution:-

We know that :-

∵ Power = Energy / Time

∴ Energy = Power × Time

=> Energy = 600 W × 8h

=> Energy = 4800 Wh

Now let's convert the energy from

Wh to kWh.

=> 1 Wh = 0.001 kWh

=> 4800 Wh = 4800(0.001)

=> 4.8 kWh

Thus, energy consumed by the refrigerator in one day is 4.8 kWh [ Option.c ]

Some Extra Information:-

• kWh is a commercial unit of energy

used by electricity boards.

• If power is in kW and time is in h, then

the unit of energy is kWh.

• 1 kWh = 1 kW × 1h

= 1000 W × 3600s

= 3.6×10⁶ J