Question

Lissajous patterns on a CRO are used to measure

• A. Voltage and current only
• B. Frequency and phase difference
• C. Resistance and inductance
• D. Power factor only

Hint:

Lissajous patterns are used in CRO to compare frequencies and measure phase difference between two signals.

Answer 1

The Correct Option is B

Concept: A Cathode Ray Oscilloscope can display waveforms and Lissajous figures by applying signals to both horizontal and vertical plates.

Step 1: When two sinusoidal signals are applied to the CRO plates, a Lissajous pattern is formed.

Step 2: The shape of this pattern depends on frequency ratio and phase difference.

Step 3: Hence, Lissajous figures are useful for comparing unknown frequency with known frequency.

Step 4: They are also used to determine phase angle between two signals. Therefore: \[ \boxed{\text{Frequency and phase difference}} \]