Question

A radio set of 60 watts runs for 50hours . How many units of electrical energy are consumed
?

Answer 1

1 W= 1J/s
60W=60J/s
the radio runs for 50 hours so 
energy expended=60J/s ×3600s×50=10800000 J
to get it in terms of units  we have to divide by 3.6×10^6.
we get energy expended =3 units.


I hope that helps you.

Answer 2

3 units of electrical energy are consumed by the radio set.

Given:

The Power of the radio set = 60 Watts

The time for which the radio set is run = 50 hours

To Find:

The units of electrical energy consumed by the radio set.

Solution:

The relationship between the Electrical energy consumed (W), Power (P) and Time (T) is:

      $\fbox{\boldsymbol{Electrical \:energy \:consumed(W)=Power(P)\times Time(T)}}$

In the given question:

The Power of the radio set (P) = 60 Watts

The time for which the radio set is run (T)= 50 hours

∴ The Electrical energy consumed (W) = 60 × 50 = 3000 Watt-hours

∴ The Electrical energy consumed (W) = 3000 Watt-hours = 3 kWh

∵ One kilowatt-hour (kWh) is equivalent to 1 unit of electrical energy.

∴ The Electrical energy consumed (W) = 3 kWh = 3 units

Therefore 3 units of electrical energy are consumed by the radio set.

#SPJ3