Which among the following statements is/are correct?

Options

A. The principle of a bimetallic strip is unequal expansion of metals.
B. An iron ring is cooled to fix it on a wooden wheel.
C. When the room temperature is raised, a pendu lum clock loses time.
D. Both (a) and (c).

Answer

(b and d)

Explanation

When a bimetallic strip is heated, it bends as one metal expands more than the other.
Option (a) is correct.
When iron ring is heated, it expands and when cooled, it contracts.
Option (b) is correct.
When the room temperature is increased, the length of the pendulum increases, and hence, the time period increases. Therefore, it takes more time to complete one oscillation. So, the pendulum clock loses time.
Option (c) is correct.