What will be the force constant of the spring system shown in the figure

Options

A. `(K_(1))/(2)+K_(2)`
B. `[(1)/(2K_(1))+(1)/(K_(2))]^(-1)`
C. `(1)/(2K_(1))+(1)/(K_(2))`
D. `[(2)/(K_(1))+(1)/(K_(1))]^(-1)`

Answer

B

Explanation

`K_(eq)=((K_(1)+K_(1))K_(2))/(K_(1)+K_(1)+K_(2))=(2K_(1)K_(2))/(2K_(1)+K_(2))`
`K_(eq)=[(1)/(2K_(1))+(1)/(K_(2))]^(-1)`