Question

Solid metallic cuboid of homogeneous material having geometrical dimension as shown in figure will have ratio of resistances for the sense of current along X, Y and Z directions respectively-

• A. a : b : c
• B. a : c : b
• C. a² : b² : c²
• D. a² : c² : b²

Answer 1

Answer: (D)

a² : c² : b²

Answer 2

R_X = $\frac{\rho a}{bc}$ R_Y = $\frac{\rho c}{ab}$ R_Z = $\frac{\rho b}{ac}$

R_X : R_Y : R_Z : : $\frac{a}{bc}$ : $\frac{c}{ab}$ : $\frac{b}{ac}$

: : a² : c² : b² (multiply each ratio by abc)