List of top Physics Questions on mechanical properties of solids asked in BCECE

A spring of force constant 800 N$m^{-1}$ has an extension of 5 cm. The work done in extending it from 5 cm to 15 cm is

A wire elongates by $ l \,mm$ when a load w is hanged from it. If the wire goes over a pulley and two weights w each are hung at the two ends, the elongation of the wire will be (in mm):