Question

An electric heater rated 400 w operates 5 hours/day. What is the
cost of energy to operate it for 30 days at Rs. 3 per unit.​

Answer 1

Hope so that it was useful

Answer 2

Rs.180

Step-by-step explanation:

Given:

• Power of electric heater = 400 W
• Time taken = 5 hours/day

To find:

• Electrical energy
• Cost of energy to operate it for 30 days at Rs. 3 per unit.

Solution:

First, let us convert the power into kilowatt-hour units.

→ Power = 400 W

→ Power = 400/1000 kW

→ Power = 4/10 kW

→ Power = 0.4 kW

We know that time taken is 5 hours for one day. Then, time taken for 30 days would be 30×5 = 150 hours.

To find the electrical energy, we use the formula:

→ Electrical energy = Power × Time

→ Electrical energy = 0.4 kW × 150 h

→ Electrical energy = 0.4 kW × 150 h

→ Electrical energy = 60 kWh

Cost of energy to operate it for 30 days at Rs. 3 would be:

→ Cost of energy = 60× 3

→ Cost of energy = Rs.180

Cost of energy to operate it for 30 days at Rs. 3 would be Rs.180.