Question

For the effective radiation of heat by an electric room heater, which of the following can be done to the reflector panel?

• A. Paint it red
• B. Polish it
• C. Paint it green
• D. Paint it black

Answer 1

The correct option is B Polish it

Polished surfaces are good reflectors of heat. Hence, it will reflect most of the radiations falling on it and send the heat waves to the surroundings. This will improve the efficiency of the heater.
Black colour absorbs most of the incident heat and hence, is not desirable for this application.