Which circuit element is associated with a positive phase-angle difference?

Which circuit element is associated with a positive phase-angle difference?

• A. A resistor
• B. An inductor
• C. A capacitor
• D. A transformer

Answer: (C)

The circuit element associated with a positive phase-angle difference is a capacitor. In an AC circuit, the relationship between voltage and current can be described in terms of phase angles, which indicate how the current waveform relates to the voltage waveform. For a capacitor, the current leads the voltage by 90 degrees (or π/2 radians). This means that when the voltage across the capacitor reaches its peak, the current is already at its peak about a quarter cycle earlier. This leading relationship results in a positive phase angle when measured with respect to the reference (in this case, voltage). In contrast, inductors exhibit a negative phase angle because the current lags behind the voltage by 90 degrees. Resistors do not cause any phase shift, resulting in a zero phase angle. Transformers, depending on their design and operation, may be associated with phase shifts, but their primary function is not directly tied to a consistent positive phase angle like that of capacitors. Thus, capacitors are recognized for creating a condition where the current is ahead of the voltage, establishing a clear association with a positive phase-angle difference.

The circuit element associated with a positive phase-angle difference is a capacitor. In an AC circuit, the relationship between voltage and current can be described in terms of phase angles, which indicate how the current waveform relates to the voltage waveform.

For a capacitor, the current leads the voltage by 90 degrees (or π/2 radians). This means that when the voltage across the capacitor reaches its peak, the current is already at its peak about a quarter cycle earlier. This leading relationship results in a positive phase angle when measured with respect to the reference (in this case, voltage).

In contrast, inductors exhibit a negative phase angle because the current lags behind the voltage by 90 degrees. Resistors do not cause any phase shift, resulting in a zero phase angle. Transformers, depending on their design and operation, may be associated with phase shifts, but their primary function is not directly tied to a consistent positive phase angle like that of capacitors. Thus, capacitors are recognized for creating a condition where the current is ahead of the voltage, establishing a clear association with a positive phase-angle difference.