A rectangular block of size `10 cm xx 8 cm xx 5 cm` is kept in three different positions P,Q and R in turns as shown in the figure. In each case, the shaded area is rigidly fixed and a definite force F is applied tangentially to the opposite face to deform the black. The displacement of the upper face will be

Options

A. same in all the three cases
B. maximum in p position
C. maximum in Q position
D. miximum in R position

Answer

C

Explanation

(c) `eta=(F//A)/(x//L)implies x=(L)/(eta)xx(F)/(A)`
If `eta` and F are constant then `x prop (L)/(A)`
For maximum displacement area at which force applied should be minimum and vertical side should be maximum , this is given in the Q position of rectangular block.