In a circuit, if the cross-sectional area increases while the length remains the same, the current for a fixed voltage will

In a circuit, if the cross-sectional area increases while the length remains the same, the current for a fixed voltage will

• A. increase
• B. stay the same
• C. decrease
• D. double

Answer: (A)

Resistance is inversely proportional to cross-sectional area for a given length and material. When the cross-sectional area increases, the conductor offers more paths for electrons, so its opposition to current (resistance) drops: R = ρL/A. With a fixed supply voltage, current is I = V/R, so as resistance falls, current rises. Therefore, increasing the area leads to an increase in current. If the area doubles, resistance halves, and the current doubles.

Resistance is inversely proportional to cross-sectional area for a given length and material. When the cross-sectional area increases, the conductor offers more paths for electrons, so its opposition to current (resistance) drops: R = ρL/A. With a fixed supply voltage, current is I = V/R, so as resistance falls, current rises. Therefore, increasing the area leads to an increase in current. If the area doubles, resistance halves, and the current doubles.