Aim:To study the charecteristics and verification of stability action of Zener diode

 Aim : To study the charecteristics and verification of stability action of Zener diode 

Apperatus : Zener diode, DC Battery , voltmeter

Miliammeter etc.

Formula : Static Resistance = V/I

                   Dynamic Resistance = ∆V/ ∆I

Diagram : 

Procedure : 1) Make the connection as shown in circkt diagram. Here the Zener diode is connected in reverse biased mode.

2) Start increasing the voltage by 0.1V steps.

3) Note down the value of voltage where you first find the current in millimetre.

4) Go on increasing the value of Voltage from voltmeter. Note down the corresponding values of current. Note down the voltage at which current suddenly increases.

5) Draw a graph of Voltage Vs Current in third quadrant because the zener diode is connected in reverse biased mode.

6) Calculate the value of Resistance from the formula.

7) Interprete your Result with SI unit.

8) Write the conclusion from the observed 

Results :

1) The Breakdown Voltage for Zener diode is......V

 2) The calculated value of Static Resistance is.....ohm

 3) The calculated value of Dynamic resistance is...ohm

To study the charecteristics of Silicon and Germanium diode and their comparison

Aim : To study the charecteristics of Silicon and Germanium diode  and their comparison

Apperatus : pn junction diode of silicon and germanium.

Formula : Static Resistance = V/I

                   Dynamic Resistance = ∆V/ ∆I

Diagram : 

Procedure : 1) Make the connection as shown in circkt diagram.

2) Start increasing the voltage by 0.1V steps.

3) Note down the value of voltage where you first find the current in millimetre.

4) Go on increasing the value of Voltage from voltmeter. Note down the corresponding values of current.

5) Draw a graph of Voltage Vs Current.

6) Calculate the value of Resistance from the formula.

7) Interprete your Result with SI unit.

8) Repeat the above steps 1) to 7) for second diode

9) Compare their Results and note that which diode is more conducive. Write the conclusion from the observed Results.

Result :

1) The Cut-in Voltage for Germanium and Silicon diodes are....... and.......

 2) The calculated value of Static Resistance is.....

 3) The calculated value of Dynamic resistance is....

CRO II - To measure Phase shift between the two Sinusoidal Signal:Practical - BSc V SEM

Aim : To measure Phase shift between the two Sinusoidal Signal.

Apparatus : CRO (Cathode Ray Oscilloscope), Function Generator, cods, Resistance box, capacitance box etc
Formula :     Phase shift = tan^-1(1/2πf C R)
                       Phase shift = (Δ x/x) 360⁰
  where,                    

  C - Capacitance
  R - Resistance

 Δ x - Divisions (Peak of y signal to Peak of X signal)  
     x - Divisions (Peak to Peak of Y signal)

 f - Frequency from function Generator  

Diagram : (circuit)

Procedure : 

Calculation of Phase shift

1) Switch ON CRO , keep it in duel Mode.
2) Adjust Focus , intensity, can role knob and CH1, CH2 position knob to get two sharp horizontal trace on CRO.
3) Make connections as shown in figure.

4) Now set the time/div and v/div knobs of CH1 and CH2 to get suitable waveform.
5) Align both the sine waves of CH1 and CH2 for selected frequency from function Generator in the interval of 500 Hz.

6) Set the Sine wave on the screen of CRO for both the signals and measure Peak to peak distance between CH1 and CH2.( Δ x )

7) Take the peak to peak distance of CH1's sign wave as x.

8) Multiply the ratio above readings by 360⁰. We get calculated Phase Shift.

9) Take the theoretical value of Phase shift. We get theorotical Phase Shift.

10) Finally check whether this calculated value of  phase shift is matched with the theorotical Phase Shift or not.
11) Repeat the above procedure for another combination of R and C.

Observation Table : 

Sr. No.	Applied Frequency (F.G.)	R	C	Δ x	x	Phase shift = tan-1 (1/2πf C R)	Phase shift = (Δ x/x) 3600
1.
2.
3.
4.
5.

Table : Calculation of Phase Shift

 Result : The Practical values of  Phase Shift and the theoretical Phase Shift are in good agreement or different combinations of f, C, R.

Precautions :1) Do not use CRO in dusty condition.2) The knobs of CRO are in released Position.3) Do not increase the brightness of CRO, it not necessary.

CRO I - Calibration of Sine Wave:Practical- BE II SEM - ADVANCED PHYSICS

Aim : To Calibrate the Sinusoidal Wave

Apparatus : CRO (Cathode Ray Oscilloscope), Function Generator, cods etc
Formula :     T = t X Δ x     

                      Frequency= 1/ T = f   

  where,     t - times per divisions (reading)

 Δ x - Divisions (Peak to Peak difference)  

 f - Frequency from function Generator  

Diagram : (circuit)

Procedure : 

Calibration of Sinusoidal Wave

1) For Calibration of the Sinusoidal wave make the connections as shown in figure.

2) Check whether all the knobs of CRO are in released Position.

3) Now set the frequency from function Generator in the interval of 500 Hz.

4) Set the Sine wave on the screen of CRO such that only 2 to 3 peaks should be seen on the screen of CRO.

5) Take the peak to peak distance of sign wave as Δ x.

6) Multiply Time/div by the divisions i.e by Δ x. We get T(Time).

7) Take the reciprocal of Time. We get Frequency.

8) Finally check whether this calculated value of frequency is matched with the frequency from function generator or not.

Observation Table : 

Sr. No.	Applied Frequency (F.G.)	Time/div (a)	Peak-peak distance(b)	Time  T= (a) X (b)	Frequency F = 1/T
1.
2.
3.
4.
5.

Table: Measurement of Frequency by calibration of sine wave.

 Result : The Practical values of frequency and frequency from function generator are in good agreement. So for each value of selected frequency sine wave is calibrated.

Precautions :1) Do not use CRO in dusty condition.2) The knobs of CRO are in released Position.3) Do not increase the brightness of CRO, it not necessary.

To Determine the wavelength of sodium light using plane transmission grating :Practical

Aim : To Determine the wavelength of sodium light using Plane transmission grating.
Apparatus : Diffraction grating, Spectrometer , Source of monochromatic sodium light, prism etc.
Formula :        

 where,

 λ _{- Wavelength of Sodium Light}

 (a + b) _{- Grating element which is given by}                      

                  _{(a+b)=2.54/15000}

 _{θn - Angle of diffraction for order n}

    n  - Order of spectrum

Diagram : 

Grating producing Central Maxima

First order diffraction spectrum Produced by grating

Procedure : 

1) Keep the Grating on prism table of the spectrometer and observe the Principal Maxima through telescope.

2) Rotate the telescope on either side(R.H.S.) of Principle maxima, the first order maxima will be observed. Measure the angle from W1 and W2.

3) Rotate the telescope again on same side so that the second order  maxima, will be observed. Measure the angle from W1 and W2.

4) Rotate the telescope on other side of Principle maxima, the first order maxima will be observed identical with the first observed maxima. Measure the angle from say W1' and W2'.

5) Rotate the telescope again on same side (i.e other side L.H.S) so that the second order  maxima from other side will be observed. Measure the angle from say W1' and W2'.

6) Calculate the first order and second order maxima with the help of observation table.

7) Now Calculate the wavelength of Sodium Source for first order and second order maxima.

Observation Table :

  

Order of spectrum	Window No.	RHS Spectrum (P)				LHS Spectrum  (Q)				Angle of Diffraction
		MSR	VSR	VSRX LC	TR	MSR	VSR	VSRX LC	TR	(P~Q)/2
I	W1
	W2
II	W1
	W2

Result :  The  Wavelength of Sodium Source is  _____ .

Precautions :

1) Slit should be narrow and bright

2) The axis of telescope , collimeter and prism should be horizontal.

3) Both windows vernier scales should be set so that the error due to rotation of telescope should be eliminated.

Study of Double Refraction by Quartz Prism- Write Up : Practical- BE II SEM - ADVANCED PHYSICS

Aim : To Determine the Principle Refractive Index for Ordinary and Extra-Ordinary Ray when refraction takes plalce through Quartz Prism.
Apparatus : A Source of Sodium Light, Spectrometer , Spirit level, Quartz Prism.
Formula : 
                

 where,

 μ_{o - RI for o-ray}

 μ_{e- RI for e-ray}

 _{δme - Angle of minimum deviation for extra ordinary ray}

  δmo - Angle of minimum deviation for ordinary ray

      A  - Angle of Prism

Diagram : 

(a) Ray Diagram

(b) Measurement of angle of Prism

(c)  Measurement of angle of minimum deviation

Procedure : 

A) Leading of Spectrometer

1) Base of the spectrometer is to be leveled with the help of screws provided at the bottom of the spectrometer using spirit level.

2) The axis of telescope , collimeter and prism should be adjusted.

3) The axis of rotation of telescope should be vertical.
B) Measurement of Angle of Prism

1) Make the arrangement as shown in figure (b)Place the Prism on Prism table so that its refracting edge A is at the center of table and rough surface BC parallel to the ground lines on the Prism table. The light falls symmetrically on both the faces AB and AC.

2) Turn the telescope towards the face AB to receive reflected image and taken it on cross wire. Note down the reading say W1 and W2.

3) Turn the telescope towards the face AC to receive reflected image and taken it on cross wire. Note down the reading say W1' and W2'.

C) Measurement of Angle of minimum deviation

1) Make the arrangement as shown in figure (c). Bring the rough side of prism on either left or right side of prism table.let it be on right side of prism table. 

2) Observe the direct ray from telescope without any deviation from the original position. Focus the direct ray with the help of the telescope  to receive double refracted image and taken it on cross wire. Note down the reading say W1 and W2. 

3) Turn the telescope towards the rough face of prism to receive deviated image either o or e ray. Receive first deviated image o-ray from direct ray and taken it on cross wire. Note down the reading say W1' and W2'.

4) Now turn the telescope towards the right side to receive the second deviated image say e-ray. Receive second deviated image e-ray from direct ray and taken it on cross wire. Note down the reading say W1'' and W2''.

Observation Table :   

Window No.	Reflection from face AB (P)				Reflection from face AC (Q)				Angle of Prism (Mean)
	MSR	VSR	VSRX LC	TR	MSR	VSR	VSRX LC	TR	(P~Q)/2
W1
W2

Table (1)  Measurement of Angle of Prism

Window No.

Direct Ray (P)

Ordinary Ray

Extra-Ordinary Ray

Angle of Minimum Deviation (Mean)

MSR

VSR

VSRX LC

TR

MSR

VSR

VSRX LC

TR

MSR

VSR

VSRX LC

TR

Direct ray ~ (Ordinary/Extra- ordinary ray)

W1

W2

Table (2) Measurement of Angle of minimum deviation

 Result :  The Principle Refractive Index for ordinary and extraordinary rays for Quartz Prism are _____ and_____ respectively.

Precautions :

1) Slit should be narrow and bright

2) The axis of telescope , collimeter and prism should be horizontal.

3) Both windows vernier scales should be set so that the error due to rotation of telescope should be eliminated.