IMPORTANT QUESTIONS IN ENGINEERING PHYSICS I PH2111 SUBJECT FOR JAN JANUARY 2012 EXAMINATION AU ANNA UNIVERSITY,CHENNAI FOR FIRST YEAR FIRST SEMESTER STUDENTS COMMAN TO ALL TAMILNADU ENGINEERING COLLEGES AFFILIATED TO AU,CHENNAI

**APPLICABLE TO CHENNAI,MADURAI,COIMBATORE,TRICHY,TRINELVELI AND ALL DISTRICT COLLEGES FIRST YEAR FIRST SEMESTER STUDENTS**

PH2111 - ENGINEERING PHYSICS I

UNIT I

1. Explain the construction and working of piezo electric generator to produce ultrasonic waves.

2. Explain the construction and production of ultrasonic waves using magnetostriction method with neat diagram

3. Discuss the pulse echo system to identify the flaws using ultrasonics with neat detailed diagram

4. Describe the method of determining the velocity of ultrasonic waves using acoustic grating

UNIT II

1. Explain the construction and working of He-Ne laser using a neat energy level diagram

2. For atomic transitions, derive Einstein’s relations and hence deduce the expression for the ratio of spontaneous emission rate to the stimulated emission rate.

3. Explain the modes of vibration of CO

_{2}molecule. Describe the construction and working of CO_{2}laser with necessary diagram.4. Explain the principle, construction and working of a semiconductor hetero junction laser with necessary diagrams. Mention any two advantages of them.

UNIT III

1. Derive an expression for the numerical aperture and angle of acceptance of fiber in terms of refractive index of the core and cladding of the fiber.

2. Describe the double –crucible technique for producing optical fibers

3. Explain with a neat block diagram, the working of a fiber optical communication system

4. Describe the principle , construction and working of light emitting diode

UNIT IV

1. Discuss in details Compton Effect its experimental verification.

2. Derive Planck’s law for black body radiation and hence deduce Wien’s law and Rayleigh Jean’s law

3. Explain the working of TEM and SEM with neat diagram

4. Derive time independent Schrödinger wave equation and hence deduce time dependent Schrödinger wave equation

UNIT V

1. Explain in detail about crystal defects with neat diagram

2. Define the terms Atomic radius and packing factor. Calculate the same for BCC and FCC structures.

3. Explain in detail the crystal structures of Diamond, Graphite, Nacl and Zns.

4. Derive an expression for the inter planar spacing for (hkl) planes of a cubic structures.