JEE PYQ: Thermal Properties Of Matter Question 18
Question 18 - 2019 (11 Jan 2019 Shift 2)
Two rods A and B of identical dimensions are at temperature 30°C. If A is heated upto 180°C and B upto T°C, then the new lengths are the same. If the ratio of the coefficients of linear expansion of A and B is 4 : 3, then the value of T is:
(1) 230°C
(2) 270°C
(3) 200°C
(4) 250°C
Show Answer
Answer: (1)
Solution
$\Delta l_1 = \Delta l_2 \Rightarrow l\alpha_A(180-30) = l\alpha_B(T-30)$. With $\frac{\alpha_A}{\alpha_B} = \frac{4}{3}$: $\frac{4}{3} = \frac{T-30}{150} \Rightarrow T = 230°C$
BETA
