Lissajous Pattern Formation
A Lissajous pattern, also known as a Lissajous figure, is a parametric curve used to represent the relationship between two sinusoidal oscillations acting at right angles to each other.
The fundamental requirements for creating a Lissajous pattern are:
- Two Sine Waves: The pattern originates from two independent sinusoidal signals.
- Perpendicular Oscillation: These sine waves must oscillate perpendicularly. Typically, one wave drives the horizontal (x-axis) motion, and the other drives the vertical (y-axis) motion.
- Phase and Amplitude Dependence: The resulting shape of the Lissajous figure is determined by the amplitudes, frequencies, and phase difference between the two sine waves.
When these conditions are met, the combined motion traces out the characteristic Lissajous pattern. This method is commonly visualized using an oscilloscope.
Therefore, the correct method involves drawing two sine waves that are perpendicular to each other.
Important Questions from Cathode Ray Oscilloscope
The function of a trigger level knob on a CRO is:
Aquadag coating is most commonly used in CROs to:
CRO stands for:
Calculate the maximum velocity of the beam of electrons in a CRT having a cathode and anode voltage of 182 V. Assume that the electrons leave the cathode with zero velocity. (Charge of electron = 1.6 × 10-19 C and mass of electron = 9.1 × 10-31 kg)
Which of the following expression is the correct formulae for the deflection sensitivity ‘S’ of a CRT, if
D = deflection on the fluorescent screen
L = distance from the center of the deflection plates to the screen
Ld = effective length of the deflection plates
d = distances between the deflection plates
Ed = Potential between deflecting plates
Ea = accelerating voltage
