Question

Q. Calculate the annual energy

consumption, in kW-h, of
a hair dryer that is rated
at 1400 W and is used for
7.0 min every day.
(The answer in the textbook is 60 kW•h)

Answer 1

60 kWh

Step-by-step explanation:

The computation of the annual energy consumption in KW-h is shown below:

As we know that

1 kw = 1000 w

So, for 1400 W it would be

= 1,400 ÷ 1,000

= 1.4 kW

Now the number of hours it used in a year

= 7 minutes × 365 days ÷ 60 minutes

= 42.58333 hours

So in one year it used

= 1.4 kW × 42.58333

= 59.61 kWh

= 60 kWh