Adding resistors in series will cause what to occur in the circuit?

• A. The current will increase
• B. The resistance will decrease
• C. The voltage will drop
• D. The power will rise

Answer: (C)

In a series circuit, the same current flows through every component and the voltages across the components add up to the source voltage. When you add resistors in series, the total resistance increases. With a fixed voltage source, that higher total resistance causes the current to fall (I = V / R_total). Because the current is smaller, the way the voltage is dropped across the chain changes, but the sum of all those drops still equals the source voltage. So the effect you observe is a reduction in current and a redistribution of voltage drops across the resistors. The other statements—current increasing, resistance decreasing, or power rising—don’t occur with added series resistance.