THE OSCILLOSCOPE

LAB REPORT # 01

Definition:-

It is a device for drawing calibrated graphs of voltage vs. time very quickly and conveniently. Such an instrument is obviously useful for the design and repair of circuits in which voltages and currents are changing with time

            The heart of the oscilloscope is a cathode ray tube or CRT. In this device we take voltage at Y-axis and time T and X-axis. Controls are provided to select the time and voltage scales needed for any given situation. The structure of Oscilloscope is given below

APPARATUS:-

·        CRO

·        Connecting Wires

·        Function Generator

PROCEDURE:-

First of all we need to calibrate the oscilloscope. To do so we have to bring the graphical line to the origin by adjusting the position from the vertical and horizontal buttons. After Calibration we connect the function generator with the CRO with connecting wires. After that a sine wave is shown on the display screen of CRO as shown in the diagram below. Now adjust the voltage/div and time/div to adjust the position of the wave. Note the readings and perform the calculations

           

CALCULATION OF PEAK TO PEAK VALUE:-

Then to calculate the peak to peak voltage we need to count the number of boxes which are above and below the mean position in the fig. shown they are 6

So the peak to peak value (Amplitude) is 6V

CALCULATION OF TIME PERIOD:-

Now to calculate the Time Period we need to count the number of boxes of a whole sine wave as shown in the Fig. above as shown in fig. they are 8 in number

The time period (T) is 8 squares x 0.002 = 0.016 s.

CALCULATION OF FREQUENCY:-

Now as we know that      

F = 1/T

Now put the value on T in the above equation we get

F = 1/0.016 sec

Frequency = F = 62.5 HZ

OBSERVATION AND CALCULATIONS:-

No Of Observation	Time set through CRO (mS)	Frequency set through Function Generator (kHz)	Voltage set through CRO (V)
1	0.5	1	0.2

Now first convert time into its SI unit

As the sine wave cover to boxes so

T = 0.0005*2 = 0.001sec

T = 0.001 sec

Now put the value of T in the above formula shown

F = 1/T

F = 1/0.001

F = 1000 Hz

Now to calculate peak to peak voltage

V = 0.2 V

V = 0.2*3

V = 0.6 v