Answer
(a) No
(b) Yes
(c) No
Work Step by Step
(a) We know that the copper rod will never touch the top of the ring as both the ring and the rod expand with the same coefficient of thermal expansion.
(b) We know that the aluminum rod can touch the top of the ring as the aluminum rod expands more with temperature as compared to the ring. Thus, the coefficient of thermal expansion of aluminum is more than copper.
(c) We know that the steel expands less with temperature as compared to copper and hence heating will not cause the rod to reach the top of the ring.
