Question

Two alternating quantities having same frequency but having different zero points are said to have

• A. Current difference
• B. Phase difference
• C. Zero difference
• D. Voltage difference

Hint:

Sinusoidal waveforms are represented as:
\[ v_1 = V_{\text{m}} \sin(\omega t) \]
\[ v_2 = V_{\text{m}} \sin(\omega t \pm \phi) \]
The term \(\phi\) represents the phase difference, which indicates the time shift between their respective zero crossings.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Alternating electrical quantities (such as AC voltage or current) are represented as sinusoidal waveforms that vary periodically with time.
These waveforms are characterized by their amplitude, frequency, and phase.

Step 2: Detailed Explanation:
Let us analyze the relationship between two sinusoidal waveforms of the same frequency:
- If two waveforms have the same frequency, they complete the same number of cycles per second.
- However, if they do not pass through their zero points (or peak values) at the same instant in time, they are shifted relative to each other along the time axis.
- This angular or temporal displacement between the two waveforms is defined as the phase difference (expressed in degrees or radians).
- The waveform that reaches its zero or peak point earlier is said to "lead," while the other is said to "lag."
Therefore, alternating quantities with the same frequency but different zero points have a phase difference.

Step 3: Final Answer:
The alternating quantities are said to have a phase difference. Hence, the correct option is (B).