If the supply voltage doubles while the total resistance remains constant, the total current will

If the supply voltage doubles while the total resistance remains constant, the total current will

• A. double
• B. increase fourfold
• C. remain the same
• D. increase twofold

Answer: (A)

Voltage and current are directly related when resistance stays fixed: I = V / R. If you double the voltage while the resistance remains the same, the current doubles too. For example, with V = 10 V and R = 5 Ω, the current is 2 A. If V becomes 20 V, the current becomes 20/5 = 4 A. So the current increases by a factor of two. The other possibilities don’t fit because a fourfold increase would require quadrupling the voltage or changing the resistance, which isn’t happening here. Leaving the current unchanged would require no voltage change or a compensating change in resistance. The phrasing "increase twofold" conveys the same doubling of current as "double," so the essential result is that the current doubles.

Voltage and current are directly related when resistance stays fixed: I = V / R. If you double the voltage while the resistance remains the same, the current doubles too.

For example, with V = 10 V and R = 5 Ω, the current is 2 A. If V becomes 20 V, the current becomes 20/5 = 4 A. So the current increases by a factor of two.

The other possibilities don’t fit because a fourfold increase would require quadrupling the voltage or changing the resistance, which isn’t happening here. Leaving the current unchanged would require no voltage change or a compensating change in resistance. The phrasing "increase twofold" conveys the same doubling of current as "double," so the essential result is that the current doubles.