On stretching a wire, the elastic energy stored per unit volume is

Explanation

The elastic energy stored per unit volume in a stretched wire can be derived from the formula for elastic potential energy, which is (1/2)F * l. When considering energy per unit volume, we must divide by the volume (A*L for a wire with cross-sectional area A and original length L). This gives us the expression Fl / 2AL. Option A is correct because it accounts for the force, extension, cross-sectional area, and original length. The other options either incorrectly include or exclude necessary terms, leading to incorrect expressions for elastic energy per unit volume.Elastic energy stored per unit volume = (1/2) × stress × strain= (1/2) × (F/A) × (l/L)= Fl / 2AL