Question

Two electric bulbs of 100 W each are used for 10 h per day in the month of September. If the price of one unit is 3 rs, then the electricity bill for two bulbs would be ______ rs.

• A. 300
• B. 380
• C. 180
• D. 280

Answer 1

The correct option is C

180

Step 1: Analyse the given situation and given data

We are given the Power of two bulbs $100\hspace{0.17em}W=0.1kW$

They are used for $10hrs$ per day in September.

So, in September total usage for 30 days is $10\times 30=300hrs$

Step 2: Calculate the Energy Consumption

We know that $Energy=Power\times time.$

So, the total energy consumed by in $kWhr$ of both the bulbs in September month will be

$0.1kW\times 2bulbs\times 300hrs=60kWhr$

Step 3: Calculate the price of energy consumed-

one unit of electricity = $1kWhr$.

The price of one unit of electricity is given 3 rs.

So, the price of $60kWhr$ will be $60\times 3=180rs$

So, the correct option will be (C) 180.