Chapter 6, Problem 15STP

To determine

To explain: The way, a refrigerator can convert more electrical energy into other forms of energy in a day than a hair dryer.

Explanation of Solution

Given: the power rating of refrigerator is 650 W and that of hair dryer is 1,000 W.

Introduction:

The rate at which electrical energy is converted to another form of energy is known as electrical power.

For the refrigerator, the power rating is 650 W or 0.65 kW, that is, the refrigerator can convert 0.65 kWh of electrical energy into other forms of energy per hour.

On the other hand, the hair dryer, having a power rating of 1000 W or 1 kW, can convert 1 kWh of electric energy to other forms of energy per hour.

However, the refrigerator converts more energy in a day because it is used continuously throughout the day, unlike the dryer, which might be used for a few hours.

Conclusion:

Thus not only the power rating of an appliance but also the number of hours the appliance is used, determines the energy converted by the appliance.