If S1 is closed in the circuit, what happens to the total current?

If S1 is closed in the circuit, what happens to the total current?

• A. Current would decrease.
• B. Current would increase.
• C. Total current remains the same.
• D. Current would reverse direction.

Answer: (B)

Closing the switch adds a new conducting path, which lowers the circuit’s total resistance. With a fixed voltage source, current from the source is I = V / Rtotal, so when S1 is closed and Rtotal drops, the total current increases. This happens because the circuit gains an additional parallel path or a short that reduces resistance, allowing more current to flow from the source. The direction of current in a simple DC circuit doesn’t flip just from closing a switch, and the current wouldn’t stay the same if resistance changes, so increasing is the correct outcome.

Closing the switch adds a new conducting path, which lowers the circuit’s total resistance. With a fixed voltage source, current from the source is I = V / Rtotal, so when S1 is closed and Rtotal drops, the total current increases. This happens because the circuit gains an additional parallel path or a short that reduces resistance, allowing more current to flow from the source. The direction of current in a simple DC circuit doesn’t flip just from closing a switch, and the current wouldn’t stay the same if resistance changes, so increasing is the correct outcome.