The slope of T2 vs l graph for a simple pendulum is
4π2g
The slope of T2 vs l graph is found to be constant at any place and is equal to 4π2g where g is the acceleration due to gravity at that place.
Explanation: In a T2 vs l graph, with T2 in the Y-axis and l in th X-axis, slope = T2l. We have T2=4π2lg ⇒T2l=4π2g