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....

Engg. Physics I : paper set 2 :Quantum Mechanics, Semiconductors, Ctrystallography,

Paper Set -  II

Subject: Engineering Physics I

Time: 2:00 Hours ]                                                [  Marks: 40 

INSTRUCTIONS TO CANDIDATES          

All Questions carry Equal Marks as indicated.

Solve FOUR questions as instructed

Assume suitable data

Draw neat sketches wherever necessary.

Use of calculator is permitted.

        Q1. (a)Write Plank’s Quantum Hypothesis with energy level diagram        (2)  
         (b)State any four Properties of Photons.                                                         (2)  
      (c)What is Compton Effect? Explain Compton shift with equation.
            Prove it graphically.                                                                                 (3)         
     (d)If the incident radiation is 1.16 Ă. Find the wavelength of scattered radiations at angle 45⁰.                                                                                                             (3)                                                               OR

      Q2. (a)Prove that light exhibit both wave as well as particle nature.              (2)

(    (b)Explain that the wavelength of Macroscopic bodies is insignificant in comparison  to the size of the bodies. Calculate the value for wavelength.     (2)

       (c)Explain this statement with the help of Davisson & Germer  Experiment.(3)

       (d)Find the De-broglie wavelength of an electron accelerated through a potential difference of 168 v                                                                                                 (3)  

    Q3. (a) Calculate the nearest neighboring distance for SC and BCC               (4)

       (b)Find  out APF, Co ordination No. in BCC and FCC                                  (2) 

       (c)Differentiate between Tetrahedral and Octahedral Voids.                         (2) 

      (d)Molybdenum belongs to BCC lattice. Its density is 10.2 X 10³ Kg/m³and its atomic weight is 95.94. Determine the radius of  Molybdenum  atom.           (2)

                                                            OR

     Q4. (a) Deduce a relation between an interlinear distance d and the Miller indices of the planes for cubic crystal.                                                                           (4)

      (b) Draw the following Miller Indices  planes [1 ̅10],[231],[112]                    (3)

      (c) Explain and deduce Bragg’s Law for X-Ray diffraction.                         (3)

     Q5. (a) Define phase velocity and group velocity.                                             (2)

     (b)Explain the application of Heisenberg’s Uncertainty principle with the help of Thought experiment.                                                                                           (4)

    (c) Explain the interpretation of wave function and write the normalization of wave function.                                                                                                     (2)     

     (d)Write 3D time dependent Schrodinger Equation.                                      (2)

                                                           OR

      Q6. (a)Write three dimensional time dependent Schrodinger Equation.    (2)

       (b)Deduce the equation for Wave function of particle confined in an infinite one dimensional potential Well of length ‘L’                                                         (4)    

       (c)Discuss the tunnling effect with the help of schrodinger  Equation.      (2)

     (d)Calculate the value of lowest two energy state for electron confined in the infinite potential well of width 15 Ǻ (m = 9.11 x 10^-31 Kg, h = 6.626 x 10^-34 J.s) (2)

     Q7. (a)Explain p-type and n- type semiconductors with suitable diagram.       (3)

          (b)Write down the Fermi - Dirac Equation for the probability of occupation of  an energy level E by an electron.                                                                            (4)

       (c)Explain how fermi level changes with increasing amounts of impurity in n-type and p-type Semiconductor.                                                                          (3)

                                                             OR

     Q8. (a)What is Hall Effect?                                                                                      (2)

       (b)Give expression for each of the following parameters Hall Voltage, Hall Coefficient, Hall Mobility.                                                                                        (6)

       (c)Mention the importance of  Hall Effect in the field of Semiconductor.         (2)