Question

Calculate the monthly bill of a heater of resistance 500,
which is used on 220 V mains, such that its daily use is
for five hours. The cost of electric energy is 4.5 Rs. per
KWh.
Monthly bill = Rs. 653.4
op
Monthly bill = Rs. 553.4
Monthly bill = Rs. 750.4
Monthly bill = Rs. 834.9​

Answer 1

Answer

• The monthly bill will be ₹522.72

Explanation

We are given that,

• Resistance = 500Ω
• Voltage = 220 V
• Cost per kWh = ₹4.5

We have to find,

• Monthly bill?

━━━━━━━━━━━━━━━━

We shall first find the Power, then the electric energy consumption per month and finally the cost!!

The Power consumed

• P = V²/R

Substituting the values,

➝ P = 220²/50

➝ 48400/50

➝ P = 968 W

➝ P = 0.968 kW

Total Time

➝ Per day 4 hours

➝ Per month 30 days

➝ Total Time = 4×30

➝ Total Time = 120 Hours

Electric Energy Consumed

• E = P × T

Substituting the values,

➝ E = 0.968 × 120

➝ E = 9.68 × 12

➝ E = 116.16 kWh

Electric Bill

➝ Monthly Bill = 116.16 × 4.5

➝ Monthly Bill = ₹522.72