The drawing shows two thin rods, one made from aluminum [a = 23 × 10-6 (Co)-1] and the other from steel [a = 12 × 10-6 (Co)-1]. Each rod has the same length and the same initial temperature and is attached at one end to an immovable wall, as shown. The temperatures of the rods are increased, both by the same amount, until the gap between the rods is closed. Where do the rods meet when the gap is closed?
(a) The rods meet exactly at the midpoint.
(b) The rods meet to the right of the midpoint.
(c) The rods meet to the left of the midpoint.

Midpoint Aluminum Steel