Question

When we pay our electricity bill, we are paying for the-
(A)Charge used
(B)Current used
(C)Power used
(D)Energy used

Answer 1

Hint: Almost all electrical devices work on electricity. Even some are electronic devices which are charged, use electricity for charging. The electricity meter installed in our homes has a reading which is taken every month and we are charged for it. The reading is in units of kiloWatt hour. So we can assume the physical quantity that is measured from the unit.

Complete step by step answer:
A meter reader pays a monthly visit to keep in account the amount of electricity consumed by us. He takes the readings in kilowatt hour and the bill is based on it by the Electrical Board.
Kilowatt is the unit of Power
Hour is the unit of time
So kilowatt hour is the unit of Power$\times $ Time
We have,
Power=\[\dfrac{Energy}{Time}\]
$\Rightarrow Energy=Power\times time$
So, kilowatt hour is the unit of Energy.
Thus the electricity bill we pay, we are paying for the Energy used.

So, the correct answer is “Option D”.

Additional Information: Charges flow in the circuit devices and keep flowing back and forth. They cannot be held by the current so we cannot measure charge. Again current is the flow of charges. So at every instant of time, the current consumed cannot be measured either as it varies a lot with time. Power is the rate of doing work which gives us no idea about the time frame in which the work is done. Hence, charge, current and power cannot be the correct options.

Note: We must know that the electricity board in our meters measures kilowatt hour and know correctly the units of power, energy and time to correctly deduce this answer out of the options given. Since all the options are related to electricity, it can be confusing, so out of the options, we must know which of them is effectively measurable in standards of consumption.