A uniform copper rod of length 50 cm and diameter 3.0 mm is kept on a frictionless horizontal surface at 20° C. The coefficient of linear expansion of copper is 2.0 × 10-5 K -1 and Young's modulus is 1.2 × 1011 N / m 2. The copper rod is heated to 100° C, then the tension developed in the copper rod is

Question

A uniform copper rod of length 50 cm and diameter 3.0 mm is kept on a frictionless horizontal surface at 20° C. The coefficient of linear expansion of copper is 2.0 × 10-5 K -1 and Young's modulus is 1.2 × 1011 N / m 2. The copper rod is heated to 100° C, then the tension developed in the copper rod is (A) 12 × 103 N (B) 36 × 103 N (C) 18 × 103 N (D) Zero

Tardigrade Admin · Accepted Answer

Since the rod is not bounded, No compressive stress hence no tensions

$12 \times 1 0^{3} N$

$36 \times 1 0^{3} N$

$18 \times 1 0^{3} N$

Zero

Since the rod is not bounded, No compressive stress
hence no tensions

12×103N

36×103N