Question

Two bars ot copper having same length but unequal diameter are heated to the same temperature. The change in length will be

• A. more in thinner bar
• B. more in thicker bar
• C. same for both the bars
• D. determined by the ratio of length and diameter of the bars

Answer 1

Answer: (C)

same for both the bars

Answer 2

$\Delta l=l \alpha \Delta \theta$ $\Delta \theta=$ change in temperature $\Delta \theta=$ same for both bars $\therefore \Delta l=$ same $\alpha=$ same $\stackrel{h}{\rightarrow}$ Iemperature coefficient $\Delta l$ does not depend on $l=$ same length thickness of the rods $\therefore \Delta l=$ same also Al will be same