Correct option is D
Given:
Outer ring = A (larger diameter)
Inner ring = B
Gap = distance between outer ring and inner ring
Cₐ = coefficient of expansion of ring A
Cᵦ = coefficient of expansion of ring B
Concept:
Increase in size ∝ coefficient of thermal expansion
If outer ring expands more → gap increases
If inner ring expands more → gap decreases
If both expand equally → gap remains same
Solution:
Case 1:
Cₐ < Cᵦ
Inner ring expands more than outer ring.
Gap decreases.
Statement A is correct.
Case 2:
Cₐ = Cᵦ
Both rings expand equally.
Gap remains same.
Statement B is correct.
Case 3:
Cₐ > Cᵦ
Outer ring expands more than inner ring.
Gap increases.
Statement C is correct.
Final Answer: (d) A, B and C
