A bar of length L, cross sectional area A and weight W is fixed at the upper end and carries an axial pull of P at the lower end. The increase in the length of the bar is
(where, E is the Young's modulus of material)
1
\(\frac{{WL}}{{2AE}} + \frac{{PL}}{{AE}}\)
2
\(\frac{{WL}}{{2AE}} + \frac{{2PL}}{{AE}}\)
3
\(\frac{{WL}}{{AE}} + \frac{{PL}}{{AE}}\)
4
\(\frac{{WL}}{{2AE}} + \frac{{PL}}{{2AE}}\)