Magnetic Properties of Matter: Practice Problem & Solution

Short Solution (Best for NEET):

To solve this problem, we apply the core principles of Magnetic Properties of Matter. Understanding the underlying formula is key to arriving at the correct answer below:

Magnetic field $B = \frac{\mu_0 N I}{2 R}$. Since $B$ and length of wire are same, $N_1 R_1 = N_2 R_2$. With $R_1 = 2R_2$, $N_1 = N_2 / 2$. The potential difference ratio $\frac{V_1}{V_2} = \frac{I_1 R_{\text{wire}, 1}}{I_2 R_{\text{wire}, 2}} = 4$.