Question

If the temperature of a rod is increased by 10°C, its length increases by 1%. What is the percentage change in volume of the body of the same material for 10°C increase in temperature?

(a) 9%

(b) 1%

(c) 5%

(d) 3%

The question was posed to me in an international level competition.

My enquiry is from Absorption and Emission topic in section Kinetic Theory of Gases of Engineering Physics I

Answer 1

Right choice is (d) 3%

The best I can explain: ∆I/I×100=100α∆T

∆V/V×100=100γ∆T=100×3α×∆T

Hence for the same rise of temperature, an increase in volume is 3 times the increase in length.