A metal wire of length `L_1` and area of cross section A is ttached to a rigid support. Another metal wire of length `L_2` and of the same cross sectional area is attached to the free end of the first wire. A body of mass M is then suspended from the free end of the second wire, if `Y_1` and `Y_2` are the Young's moduli of the wires respectively the effective force constant of the system of two wires is

Options

A. `(Y_1Y_2A)/(2(Y_1L_2+Y_2L_1))`
B. `(Y_1Y_2A)/(L_1L_2)^(1//2)`
C. `(Y_1Y_2A)/((Y_1L_2+Y_2L_1))`
D. `((Y_1Y_2)^(1//2)A)/((L_1L_2)^(1//2))`

Answer

C