Question

A 2 kW air conditioner works for 8 hours per day. At the rate of Rs 6/kWh the electricity bill for one day will be-

• A. Rs 12
• B. Rs 24
• C. Rs 48
• D. Rs 96

Hint:

One unit of electricity is equal to one kilowatt-hour (kWh). Always calculate the number of units consumed first and then multiply by the tariff rate.

Answer 1

The Correct Option is D

Step 1: Understand the idea.
An air conditioner uses electrical energy while it runs. The energy used is found by multiplying its power by the time it works.

Step 2: Write the formula.
Energy = Power $\times$ Time. When power is in kilowatts (kW) and time is in hours (h), the energy comes out in kilowatt-hours (kWh), which we simply call units of electricity.

Step 3: Note the given values.
Power $P = 2\ kW$, time $t = 8\ hours$, and the rate of electricity is Rs 6 per kWh.

Step 4: Find the energy used in one day.
Energy $E = 2 \times 8 = 16\ kWh$. So the air conditioner uses 16 units in one day.

Step 5: Find the bill.
Each unit costs Rs 6, so the bill = $16 \times 6 = 96$ rupees.

Step 6: Check and conclude.
Rs 12, Rs 24 and Rs 48 are all too small because they ignore either the full time or the full power. The correct cost for one day is Rs 96.
\[ \boxed{\text{Rs 96}} \]