STANDARDPhysics-Thermal Expansion
STANDARD Physics Composite Rods MCQ Question
Type: MCQ-numerical-Medium
At 50°C, a brass rod has a length 50 cm and a diameter 2 mm. It is joined to a steel rod of the same length and diameter at the same temperature. The change in the length of the composite rod when it is heated to 250°C is (Coefficient of linear expansion of brass = 2.0 × 10⁻⁵°C⁻¹, coefficient of linear expansion of steel = 1.2 × 10⁻⁵°C⁻¹)
A
0.28 cm
B
0.30 cm
C
0.32 cm
D
0.34 cm
Correct Answer
Option C
Detailed Explanation
The change in length for brass is ΔL_b = α_bL_bΔT = 0.2 cm and for steel is ΔL_s = α_sL_sΔT = 0.12 cm. Total change = 0.2 cm + 0.12 cm = 0.32 cm.
Found an issue with this question?