Consider the following statements:
1. The air in a hair dryer is heated by convection.
- If air were a good conductor of heat, at night time the earth would be considerably cooler.
Which of the given statements is/are correct?
-
Only (1)
-
Only (2)
-
Both (1) and (2)
-
Neither (1) nor (2)
B
Correct answer
Explanation
(i) Statement (1) is incorrect. The air in a hair dryer is heated by radiation. The air is heated by a hot, glowing coil of wire that emits radiation.
(ii) Statement (2) is correct. If air were a good conductor of heat, at night time the earth would be considerably cooler because all the heat of earth is escaped in the space through air as a medium.