Question

An air conditioner is rated $240\,V,\,1.5\,kW$. The air conditioner is switched on for $8$ hours each day. How much electrical energy is consumed in $30$ days?
A. $360\,kWh$
B. $8.64\,kWh$
C. $120\,kWh$
D. $240\,kWh$

Answer 1

Hint:Here we can calculate the energy dissipated by multiplying the time and power. Then we can find out how much energy is consumed in $30$ days. Energy is exchanged if there is a transition in a system and part of the energy is dissipated. Dissipation is a term sometimes used to describe means of losing resources. It is claimed that any energy which is not diverted to usable energy stores is wasted because it is lost to the atmosphere.

Complete step by step answer:
If for a given time, a certain amount of electricity is dissipated, so energy is dissipated. Energy (power $ \times $ time) is estimated in joules and the energy dissipated by a part or circuit can be determined by using time ($t$) in the power formulas.

We ought to be able to measure the amount of electricity that the resistor can dissipate in order to figure out how energy dissipates. If a current I flows through a given element in your circuit, losing voltage V in the process, then that current and voltage is the sum of the power dissipated by that circuit element:$P = I \times V$

The energy (power time) is estimated in joules and the energy dissipated by a part or circuit can be determined by using time ($t$) in the power formulae.
Dissipated Energy $= P \times t$
$\Rightarrow$ Dissipated Energy $= 1.5\,kW \times 8\,h $
$\therefore$ Dissipated Energy $= 12\,kWh \\ $
For $30$ days, the energy dissipated will be: $12 \times 30 = 360\,kWh$
Thus, the electrical energy consumed by the air conditioner in $30$ days is $360\,kWh$.

Hence, option A is correct.

Note:Power dissipation should not be confused with power consumption. Energy consumption is the volume of energy used as the basis for costs paid by the utility to justify its charges. The amount of energy used in the conversion process which involves both available and unused energy, is power dissipation.