What is probably happening when an ohmmeter, connected across a circuit, initially indicates a low resistance and then shows increasing resistance with time?

What is probably happening when an ohmmeter, connected across a circuit, initially indicates a low resistance and then shows increasing resistance with time?

• A. The ohmmeter is defective
• B. The circuit contains a large capacitor
• C. The circuit contains a large inductor
• D. The circuit is a relaxation oscillator

Answer: (B)

When an ohmmeter shows an initial low resistance followed by an increase in resistance over time, it typically indicates the presence of a large capacitor in the circuit. Initially, when the ohmmeter is connected, the capacitor appears to allow current to flow, leading to a low resistance reading. However, as the capacitor begins to charge, the current flow decreases, causing the resistance reading to increase. This behavior is consistent with how capacitors work in a circuit, where they charge over time and affect resistance measurements. In contrast, other components such as inductors would not behave in the same way when measured with an ohmmeter, and a relaxation oscillator operates differently. Therefore, the observation of resistance increasing with time is closely linked to the charging process of a capacitor.

When an ohmmeter shows an initial low resistance followed by an increase in resistance over time, it typically indicates the presence of a large capacitor in the circuit. Initially, when the ohmmeter is connected, the capacitor appears to allow current to flow, leading to a low resistance reading. However, as the capacitor begins to charge, the current flow decreases, causing the resistance reading to increase. This behavior is consistent with how capacitors work in a circuit, where they charge over time and affect resistance measurements.

In contrast, other components such as inductors would not behave in the same way when measured with an ohmmeter, and a relaxation oscillator operates differently. Therefore, the observation of resistance increasing with time is closely linked to the charging process of a capacitor.