Question

Two rods of different materials having coefficients of linear expansion Q1,Q2 and Young's moduli Y, and Y2
respectively are fixed between two rigid massive walls. The rods are heated such that they undergo the same
increase in temperature. There is no bending of rods. If a : 2 = 2:3, the thermal stresses developed in the two
rods are equally provided Y, : Y, is equal to
(a) 2:3
(b) 1:1
(c) 3:2
(d) 4:9​

Answer 1

Explanation:

Y1a1=Y2a2

a1/a2=2:3

hence,Y1/Y2=3:2

F/A=Y∆L/L

and a=∆L/L

Since it is given that for both rods,thermal stress is equal.

so,Y1a1=Y2a2

So.The answer is option(c)3:2