1)

A and B are two wires. The radius of A is twice that of B. They are stretched by the same load. Then the stress on B is


A) equal to that on A

B) four times that on A

C) two times that on A

D) half that on A

Answer:

Option B

Explanation:

Stress = $\frac{Force }{Area}$

.'. $Stress \propto\frac{1}{\pi r^{2}}$

$\frac{S_{B}}{S_{A}} = \left(\frac{r_{A}}{r_{B}}\right)^2$

= 22 → SB = 4SA