Question

Calculate the total cost of running the following electrical devices in the month of September if the rate of 1 unit of electricity is Rs 6.00
(A) Electric heater of 1000 ${\text{W}}$ for 5 hours daily
(B) Electric refrigerator of 400 ${\text{W}}$ for 10 hours daily

Answer 1

We are looking for the cost consumed by the devices during the entire month. It could be simply done by calculating a day and multiplying with 30 (since the month is September).

Formula used: To calculate the cost of appliances we will apply simple basic maths and also, we will be using some unit conversions like ${\text{1000W = 1KW}}$ .

Complete step by step answer:
It is already known that electric heater consumes 1000 W for 5 hours/day:
Amount of 1 unit of electricity is Rs 6.
Since, ${\text{1KW}}$ is used for 5 hr.
So, ${\text{5KW}}$ is being used each day.
Then for 30 days = ${\text{5 \times 30 = 150KW}}$
Amount to be paid= ${\text{150 \times 6 = Rs900}}$
Similarly, for ${\text{400 W}}$ for 10 hr daily.
Therefore, consuming ${\text{4KW}}$ .
Then for 30 days = ${\text{4 \times 30 = 120KW}}$
Amount to be paid= ${\text{120 \times 6 = Rs720}}$
So, the total amount to be paid = Rs (900 + 720) = Rs 1620.

Additional Information
Our appliance and electronics allows you to estimate your annual energy use and cost to operate specific products. The wattage values provided are samples only, actual wattage of products varies depending on product age and features. Thus, on determining how much electricity our appliances and home electronics use we can understand how much money we are spending to use them. Using some information to estimate how much electricity an appliance is using and how much the electricity costs, we can decide whether to invest in a more energy-efficient appliance.

Note:
Some basic application in daily life is to know about how much we use an appliance every day we can roughly estimate the number of hours it runs. For example we can estimate the number of hours that a refrigerator actually operates at its maximum wattage. Refrigerators, although turned on all the time, actually cycle on and off as needed to maintain interior temperatures.