Question

One end of uniform wire of length $L$ and of weight $W$ is attached rigidly to a point in the roof and a weight $W_1$ is suspended from its lower end. If $s$ is the area of cross section of the wire, the stress in the wire at a height $\left(3L/4\right)$ from its lower end is

• A. $\frac{W_1}{s}$
• B. $[W_1+\frac{W}{4}]s$
• C. $[W_1+\frac{3W}{4}]s$
• D. $\frac{W_1+W}{s}$

Answer 1

The correct option is C $[W_1+\frac{3W}{4}]s$

The total weight at $\left(3L/4\right)$ from the lower end:

$Weight=W_1+\frac{3L\times W}{4\times L}$

So, the $stress=weight/area$

i.e,$stress=\frac{W_1+\frac{3W}{4}}{s}$

hence Option C is correct