A stationary closed Lissajous pattern on an oscilloscope has 3 horizontal tangencies and 2 vertical tangencies for a horizontal input with frequency 3 kHz. The frequency of the vertical input is 

The two signals S1 and S2, shown in figure, are applied to Y and X deflection plates of an oscilloscope.  

The waveform displayed on the screen is

The two inputs of a CRO are fed with two stationary periodic signals. In the X-Y mode, the screen shows a figure which changes from ellipse to circle and back to ellipse with its major axis changing orientation slowly and repeatedly. The following inference can be made from this.

Two sinusoidal signals  and  are applied to X and Y inputs of a dual channel CRO. The Lissajous figure displayed on the screen is shown below:

The signal  will be expressed as  

The simultaneous application of signals x(t) and y (t) to the horizontal and vertical plates, respectively, of an oscilloscope, produces a vertical figure-of - 8 display. If P and Q are constants, and x(t)=P sin(4t+30) , then y (t) is equal to

Group II represents the figures obtained on a CRO screen when the voltage signals  and  are given to its X and Y plates respectively and Φ is changed. Choose the correct value of Φ from Group I to match with the corresponding figure of Group II         

Group I

P.   Φ = 0          Q.  Φ =

R.         S.

Group II

Two in-phase 50 Hz sinusoidal waveform of unit amplitude are fed into channel 1 and channel 2 respectively of an oscilloscope. Assuming that the voltage scale, time scale and other settings are exactly the same for both the channels, what would be observed if the oscilloscope is operated in X-Y mode?

In an oscilloscope, the input to the horizontal plates is a 100 Hz voltage signal. The Lissajous patterns (A), (B) and (C) will be generated when different frequency voltage signals are applied to vertical plates. Match each Lissajous pattern to the corresponding frequency .

An oscilloscope is operated in the X-Y mode. The figure 8 is displayed on the oscilloscope screen. If the frequency of the X-input is 1 kHz, the Y-input frequency is _____________________.

A Lissajous pattern, as shown in figure, is observed on the screen of a CRO when voltages of frequencies  are applied to the x and y plates respectively.  is then equal to