**ENGINEERING PHYSICS – 1 Important Questions and Answers :-**

**UNIT – I – CRYSTAL PHYSICS**

1. Define the terms “Coordination number”, and “atomic radius”. Calculate the above for SC, BCC and FCC structures.

2. Describe the structure of HCP crystal. Give details about its atomic radius, atomic packing factor and axial ratio.

3. Show that atomic packing factor for FCC and HCP are equal.

4. What are Miller indices? Deduce the relation between inter planar distance‘d’ and lattice constant ‘a’.

5. Discuss in detail the structures of diamond and graphite.

6. Describe the various crystal growth techniques.

**UNIT – II – PROPERTIES OF MATTER AND THERMAL PHYSICS**

1. Describe with necessary theory, the method to determine the Young’s modulus of the material of a rectangular bar by uniform bending.

2. What is cantilever? Obtain expression for the depression at the loaded end of cantilever whose other end is fixed assuming that its own weight is not effective in bending.

3. Derive an expression for the internal bending moment of a beam in terms of radius of curvature?

4. Derive an expression for depression at the free end of a cantilever, due to load. Describe an experiment to determine the Young’s modulus of the cantilever material using this expression.

5. Write a short note on stress strain diagram.

6. How will you classify three types of elastic moduli? Explain.

7. Derive a differential equation to describe the heat conduction along a uniform bar. Hence obtain the steady solution of it.

8. Describe lee’s disc method to find the co-efficient of thermal conductivity of a bad conductor.

9. Obtain an expression for the quantity of heat conducted radially out of a hollow cylinder. Using this, explain how the thermal conductivity of rubber can be determined.

10. Derive an expression for the heat conduction through a compound media of both series and parallel.

**UNIT – III – QUANTUM PHYSICS**

1. State Planck’s Hypothesis. Derive Planck’s law for black body radiation and hence deduce Wien’s Displacement law and Rayleigh – Jean’s law.

2. What is Compton Effect? Derive the equation for Compton shift. Explain the experimental verification of Compton Effect with the diagram.

3. What is Schrodinger’s wave equation?Derive Schrödinger’s time dependent wave equation and hence deduce time independent Schrödinger wave equation.

4. Derive the expression for energy levels of a particle enclosed in one-dimensional potential box of width “a” and infinite height.

5. Describe the principle, construction and working of Scanning Electron Microscope with neat sketch.

6. Explain the principle, construction and working of Transmission Electron Microscope with neat sketch.

7. Explain how the matter waves are experimentally evidenced using G.P Thomson’s experiment.

**UNIT – IV- ACOUSTICS AND ULTRASONICS**

1. Write in detail about the factors affecting architectural acoustics and their remedies.

2. What is reverberation time? Using Sabine’s formula explains how the sound absorption coefficient of a material is determined. Derive the expression for growth and decay of sound energy.

3. Describe the production of ultrasonic waves by Magnetostriction oscillator method. Give the merits and demerits of this method.

4. Describe the production of ultrasonic waves by piezo electric oscillator method. Give the merits and demerits of this method.

5. Explain the determination of velocity of ultrasonic using an acoustical grating.

6. Draw a block diagram of ultrasonic flaw detector for NDT. Mention its advantages and disadvantages.

**UNIT – V – PHOTONICS AND FIBER OPTICS**

1. Explain with neat diagram the process of absorption of light, spontaneous emission and stimulated emission of light. What are the necessary conditions for their occurrence? Why does spontaneous emission dominate over stimulated emission at normal temperatures?

2. Explain the principle spontaneous and stimulated emission and derive the equation for Einstein’s coefficients.

3. Describe the principle, construction and working of Nd: YAG Laser.

4. Explain the principle, construction and the working of CO2 Laser.

5. Explain the principle, construction and working of Semi-Conducting homo-junction laser

6. What is meant by acceptance angle for an optical fiber? Show how it is related to numerical aperture.

7. Explain how optical fibers are classified. Discuss their characteristics features.

8. Describe the losses that occur in fiber optic communication and give the remedies for it.

9. Discuss the working of fiber optical communication system with a block diagram.

10. What are the applications of fiber optic sensor? Describe any one of the application in detail