The length of an aluminium rod is 120 cm at 20 °C. What is its length at 80 °C, if coefficient of linear expansion of aluminium is 2.5 × 10^-5/°C?

Correct answer is (A) I and II are both correct

1. The coefficient of linear expansion of a solid is defined as increase in the length per unit original length at 0 °C per degree rise in temperature. It is denoted...

1. False.  Coefficient of linear expansion is different for different substances.  2. True.

Yes, coefficient of areal expansion and coefficient of volume expansion depend upon nature of material.

Correct option is: (D) Invar steel

Correct option is: (C) 17 °C

Correct option is: (B) -30 °C

Correct option is: (A) 35 °C

(B) 68 cm LCu αCu ∆T = LAl αAl ∆T ∴ 88 × (1.7 × 10-5) = LAl(2.2 × 10-5) ∴ LAl = \(\frac{88\times1.7}{2.2}\) ∴ LAl = 68 cm

B) Square only