Engineering Physics - Question Bank

Engineering Physics - Question Bank

                                                                Unit – I     

                                 Interference & Diffraction

PART - A

1.      Explain the principle of superposition of waves.

2.      Define coherence.

3.      a) What is interference of light waves?

b) What are the conditions necessary for obtaining sustained interference fringes?

4.      Define fringe width and write its equation in the case of Young’s double slit experiment

5.      Explain interference by division of amplitude and division of wave front with examples.

6.      Distinguish between the interference and diffraction patterns of light.

7.      Distinguish between Fresnel and Fraunhofer diffraction.

8.       What is diffraction grating? Write the grating equation.

9.      What is resolving power? Explain Rayleigh’s criterion for resolving power.

10.  Explain why the central fringe is dark in Newton’s rings experiment. 

11.  When the Young’s experiment was done with blue light of 436 nm, the distance between two successive dark fringes was found to be 1.05 mm. If the distance between the sources and the screen is 1.40 m, calculate the distance between the two slits.

12.  In a Newton’s rings experiment, the diameters of the 6^th and 12^th dark rings are 0.42 cm and 0.69 cm respectively. Find the diameter of the 20^th dark ring.

13.  A parallel beam of monochromatic light is incident normally on a plane diffraction grating having 6000 lines/cm. Calculate the angular separation between the two lines of wavelengths 589 nm and 592 nm in the second order.

 

PART – B

1.      Derive the conditions for obtaining the bright and dark fringes in the Young’s double slit experiment.

2.      Discuss the interference of light reflected from a thin transparent film and obtain the conditions for observing the bright and dark fringes.

3.      Derive an expression for the radius of the n^th bright ring in the case of Newton’s rings.

4.      Prove that in the reflected light, the diameters of the Newton’s dark rings are proportional to the square roots of natural numbers.

5.      Describe the experimental procedure to find the radius of curvature of a plano-convex lens by forming Newton’s rings.

6.      What is diffraction? Distinguish between Fresnel and Fraunhofer diffractions.

7.      Discuss, in detail, Fraunhofer diffraction at single slit.

8.      Explain, in detail, Fraunhofer diffraction due to two slits.

9.      Write notes on:

                                                              i.      Diffraction grating and grating spectrum

                                                            ii.      Resolving power of a grating.

10.  Explain Rayleigh’s criterion for resolving power. How do you improve the resolving power of a telescope?

                                                        Unit – II:    

              Crystallography & X-Ray Diffraction

PART – A

1.      Distinguish crystals and amorphous solids.

2.      Define space Lattice and Unit cell.

3.      What are basic lattice parameters?

4.      Define Primitive cell. What is the difference between primitive cell and unit cell?

5.      What are Bravais lattices? Name the seven crystal systems.

6.      Define atomic radius and nearest neighbor distance.

7.      Define Co-ordination number. Write the coordination numbers of SC, BCC and FCC structures.  

8.      Define atomic packing factor. Write the coordination numbers of SC, BCC and FCC structures. 

9.      What are the lattice parameters of Hexagonal crystal structure?

10.  Name the crystal structure of the following. a) Gold b) NiSO₄ c) Bismuth d) SiO₂

11.  Derive the miller indices from  the given intercepts of the following planes : 

a) 2a, 3b, 4c                 b) 3a, 6b, 2c

12.  What are Miller indices?

13.  Lattice constant of a metal is 0.38 nm. Calculate the distance between (1 1 0) planes.

14.  Write Bragg’s equation and explain the terms involved in it.

 

PART – B

1.      What are Bravais lattices? Describe different Bravais lattices and their grouping into seven crystal systems.

2.      What is a packing factor? Obtain packing factor for SC, FCC and BCC lattices.

3.      What are Miller indices? How are they determined? Draw the crystal planes (110) and (001) in cubic unit cell.

4.      Show that for a cubic structure the inter-planar distance d in terms of Miller indices and unit cell edge a is given by .

5.      State and explain Bragg’s Law of X-ray diffraction.

6.      Explain the Laue method to analyze the crystal structure.

7.      Explain with diagrams how the powder method is used to determine the crystal structure.

 

                                                        Unit – III:   

    Quantum Mechanics & Band Theory of Solids

                                                                    PART – A

 1.         What are matter waves?

2.         Explain the de-Broglie hypothesis.

3.         What are the properties of matter waves?

4.         Calculate the wavelength associated with an electron raised to a potential 400 V.

5.         Explain Heisenberg’s Uncertainty principle.

6.         What is a wave function? Explain its physical significance.

7.         Write the potential function for a particle bound in a 1-D box .

8.         What is a normalized wave function?

9.         What are eigen values and eigen functions?

10.     An electron is bound in 1-D box of size 410^-10 m. What will be its minimum energy?

 

  PART – B

 

1.      What are matter waves? Derive an expression for De-Broglie wavelength and explain its 

        different forms.

2.      Explain the Davisson – Germer’s experiment to prove the wave nature of matter.

3.      Derive Schrodinger time-independent wave equation.

4.      For a particle confined in one-dimensional potential well, evaluate the eigen values and

eigen functions.

Tags: 

 What is the formula for interference and diffraction? What is interference with example? What is the concept of

 diffraction? What is diffraction and interference in chemistry? 

 

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