Physics · PYQ NEET UG 2016(1)

Coefficient of linear expansion of brass and steel rods are \( \alpha_1 \) and \( \alpha_2 \). Lengths of brass and steel rods are \( l_1 \) and \( l_2 \) respectively. If \( (l_2 - l_1) \) is maintained same at all temperatures, which one of the following relations holds good?

1. A
   \( \alpha_1 l_1 = \alpha_2 l_2 \)
2. B
   \( \alpha_1^2 l_2 = \alpha_2^2 l_1 \)
3. C
   \( \alpha_1 l_2 = \alpha_2 l_1 \)
4. D
   \( \alpha_1 l_1^2 = \alpha_2 l_2^2 \)