Two uniform brass rods \( A \) and \( B \) of length \( l \) and \( 2 l \) and radii \( 2 r \) a...

Two uniform brass rods \( A \) and \( B \) of length \( l \) and \( 2 l \) and radii \( 2 r \) and \( r \) respectively are heated to the same temperature. The ratio of the increase in the volume of \( A \) to that of \( B \) is
[AMU (Engg.) 2009]
(a) \( 1: 1 \)
(b) \( 1: 2 \)
(c) \( 2: 1 \)
(d) \( 1: 4 \)