In a series circuit, how does adding resistance affect total resistance and circuit current?

• A. Current remains the same; resistance increases.
• B. Total resistance increases; current decreases.
• C. Total resistance decreases; current increases.
• D. Total resistance decreases; current increases.

Answer: (B)

In a series circuit, resistors add together to form the total resistance. So when you add more resistance, the total resistance goes up. With a fixed voltage source, current follows Ohm’s law: I = V / R_total. Increasing R_total lowers the current. The same current flows through every element in a series circuit, but that current value decreases as you add resistance. The voltage across each resistor adjusts accordingly, and all drops still add up to the supply voltage.

So the best description is that total resistance increases and current decreases.