An immersion rod of 1500 watt is used 3 hour daily for heating the water. If the cost electricity is Rs 5.00 per unit, then calculate the cost of electricity consumed in 30 days.

To proceed to the question first we need to understand the meaning of 1 unit that is, 1 unit is simply equal to 1kiloWatthour or when 1000 Watt of power is consumed in 1 hour.

Now we are given with the power(P) of the immersion rod which is 1500 Watt and we are given with the time limit for each day which is 3 hours and the number of days for which the rod was used which is 30 days, so let’s calculate the total time(t) in the question, which is 3 hours × 30 days = 90 hours, we have converted into hours because of units used in power above.

We are also given with the cost of 1 unit which is Rs. 5 hence expense of 1 kWh energy and we have to calculate the amount of money spend in the month for that we have to calculate the amount of energy used in kWh.

So,

Rs. 5 = 1000Watt × 1 hour = 1kwh

Therefore we have 1500 watt power, so,

1.5 × Rs. 5 = 1500 Watt × 1 hour

We also have 90 hours of using the rod, so,

90 × 1.5 × Rs. 5 = 1500 Watt × 90 hours

Therefore the amount of money spend in the month will be Rs. 675.