Question

A block has dimensions $1\, cm\, 2\, cm$ and $3\, cm .$ Ratio of the maximum resistance to minimum resistance between any pair of opposite faces of this block is

• A. 9: 1
• B. 1: 9
• C. 18: 1
• D. 1: 6

Answer 1

Answer: (A)

$R_{\max }=\rho \frac{l_{\max }}{A_{\min }}=\rho \frac{3}{2}$
$R_{\min }=\rho \frac{l_{\min }}{A_{\max }}=\rho \frac{1}{6}$
$\therefore \frac{R_{\max }}{R_{\min }}=\frac{3}{2} \times \frac{6}{1}=9: 1$