In a circuit, when a diode is shorted, which reading will be zero volts?

In a circuit, when a diode is shorted, which reading will be zero volts?

• A. Ammeter reading
• B. Voltmeter reading
• C. Ohmmeter reading
• D. Wattmeter reading

Answer: (B)

When a diode is shorted, it acts like a wire with almost no resistance, so there is essentially no voltage drop across it. A voltmeter measures the voltage difference between two points, and across that shorted path the potential difference is effectively zero, so the reading is zero volts. The other meters measure different quantities: an ammeter would show the current in that branch, an ohmmeter would read very low resistance if used across the short (and only when measuring resistance with power off), and a wattmeter would reflect power based on voltage and current, which would be minimal here due to the near-zero voltage.

When a diode is shorted, it acts like a wire with almost no resistance, so there is essentially no voltage drop across it. A voltmeter measures the voltage difference between two points, and across that shorted path the potential difference is effectively zero, so the reading is zero volts. The other meters measure different quantities: an ammeter would show the current in that branch, an ohmmeter would read very low resistance if used across the short (and only when measuring resistance with power off), and a wattmeter would reflect power based on voltage and current, which would be minimal here due to the near-zero voltage.