Voltage drop across a switch indicates that:

Voltage drop across a switch indicates that:

• A. The switch is open
• B. The switch is closed
• C. The circuit is shorted
• D. The switch is grounded

Answer: (A)

The key idea is that a voltage difference across a switch shows whether current can flow through it. When a switch is open, it breaks the circuit so the two sides sit at different potentials, and you can measure a voltage across the gap. If the switch were closed, it would create a continuous path with only a small resistance, so the voltage drop across it would be essentially zero. A shorted path would bypass the switch and usually not produce a meaningful voltage across the switch itself, and grounding isn’t what creates the drop across the switch in normal operation. So a voltage drop across the switch indicates that the switch is open.

The key idea is that a voltage difference across a switch shows whether current can flow through it. When a switch is open, it breaks the circuit so the two sides sit at different potentials, and you can measure a voltage across the gap. If the switch were closed, it would create a continuous path with only a small resistance, so the voltage drop across it would be essentially zero. A shorted path would bypass the switch and usually not produce a meaningful voltage across the switch itself, and grounding isn’t what creates the drop across the switch in normal operation. So a voltage drop across the switch indicates that the switch is open.