Question

Consider the cylindrical element as shown in the figure. Current flowing the through element is $I$ and resistivity of material of the cylinder is $\rho$. Choose the correct option out the following

• A. Power loss in first half is four times the power loss in second half
• B. Voltage drop in first half is twice of voltage drop in second half
• C. Current density in both halves are equal
• D. Electric field in both halves is equal

Answer 1

The correct option is B Voltage drop in first half is twice of voltage drop in second half

$\frac{R_1}{R_2}=\frac{A_1}{A_2}=\frac{4}{1}$

$\frac{P_1}{P_2}=\frac{{I^{2}R}_1}{{I^{2}R}_2}=\frac{4}{1}\Rightarrow \frac{V_1}{V_2}=\frac{{I^{}R}_1}{{I^{}R}_2}=\frac{4}{1}$

$\frac{J_1}{J_2}=\frac{4}{1}$