07a1bs03 - Engineering Physics

H.TNO:________________________ Code No: 07A1BS03

Set No. 1

I B.Tech. Regular I Mid Term (Objective) Online Examinations, Dec. - 2008 ENGINEERING PHYSICS Time: 20 (Min.)

Max Marks: 20 Answer All Questions

All Questions Carry Equal Marks ***** I. Multiple choice Questions: 1. For constructive superposition the phase difference between two waves should be 1) 4 n ∏ [ ] 2) 3 n ∏ 3) 2 n ∏ 4) n ∏ 2. In young’s double slit experiment, the central spot of the fringe is 1) Bright 2) Dark 3) Partially dark 4) Partially bright

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3. Colours of thin films can be explained using 1) Dispersion 2) Interference 3) Diffraction 4) Refraction

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4. Crystalline structure of solid can be studied by using method of 1) Diffraction 2) Interference 3) Polarization 4) Refraction

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5. In Fresnel experiment the phase difference between two waves from successive half period zone is [ ] ∏ 1) 4 ∏ 2) 2 3) ∏ 4) Zero 6. In Fraunhofer double slit experiment the interference maximum occurs at θ = 1) Zero [ ] 2) 900 3) 1800 4) 2700 Contd……(2)

:2: 7. In which experiment lenses are required 1) Fresnel’s diffraction 2) Fraunhofer diffraction 3) Both Fresnel’s diffraction and Fraunhofer diffraction 4) None

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8. What is the highest order spectrum which may be seen with monochromatic light of wave length of 6000 A0, by means of a diffraction grating with 5000 lines/cm? 1) 5 [ ] 2) 4 3) 3 4) 2 9. Which of the following properties proved that light waves are transverse in nature 1) Dispersion [ ] 2) Interference 3) Diffraction 4) Polarization 10. 1) 2) 3) 4)

When light ray passes through calcite prism it undergoes Rectilinear propagation Reflection Double refraction Interference

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II. Fill in the Blanks: 11. The propagation of ultrasonic waves depends on _____ of media 12. As a result of magnetostriction method ____ will be emitted. 13. In ultrasonics, detection of flaws in solids is mainly based on ________ principle. 14. Ultrasonic velocity increases with increasing ________. 15. Metals can be soldered or brazed by subjecting them to _____ vibrations. III. True/False Statement: 16. In a good acoustical auditorium the sound should be uniform in the entire auditorium. (True/False) 17. An echo is produced when the reflected sound reaches to audience after the direct sound. (True/False) 18. The reverberation time is inversely proportional to volume. (True/False) Contd……(3)

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19. Open window unit is also called as Henry.

(True/False)

20. The structural noise can be reduced by using double walls and air space between them. (True/False) -o0o-

H.TNO:________________________ Code No: 07A1BS03

Set No. 2

I B.Tech. Regular I Mid Term (Objective) Online Examinations, Dec. - 2008 ENGINEERING PHYSICS Time: 20 (Min.)

Max Marks: 20 Answer All Questions

All Questions Carry Equal Marks ***** I. Multiple choice Questions: 1. Superimposing of Waves suitably produces 1) Interference 2) Diffraction 3) Polarization 4) Reflection

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2. If young’s double slit experiment shifted from air to water medium, then the fringe width becomes [ ] 1) Infinite 2) Decreases 3) Increases 4) Un affected 3. Interference in thin films is due to 1) Division of wavelength 2) Division of amplitude 3) Division of reflected light 4) Division of particles

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4. The center of Newton’s ring experiment appeared 1) Dark 2) Bright 3) Partially dark 4) Partially bright

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5. The path difference between two successive Fresnel’s Zones is 1) λ / 6 2) λ / 4 3) λ / 2 4) λ

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6. In Fraunhofer double slit experiment the intensity maxima and minima proportional to [ ] 1) Distance between the slits 2) Brightness of the light 3) Slits width 4) Square of the number of the slits Contd……(2)

:2: 7. Diffraction grating means 1) Large number of equidistant slits 2) Circular slit 3) More than two slits 4) Large number of random distance slits

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8. First minimum of diffraction pattern using circular aperture of diameter d is given by sin θ = [ ] 1) 0.22 2) 1.22 3) 1.45 4) 2.45

λ d

λ d

λ d

λ

d 9. Polaroid produces 1) Plane polarized light 2) Circularly polarized light 3) Elliptically polarized light 4) Unpolarized light 10. The linearly polarized light is split into two rays due to 1) Polarization 2) Diffraction 3) Double refraction 4) Reflection

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II. Fill in the Blanks: 11. Ultrasonic waves travel with a velocity of _____ waves 12. Quartz crystal will exhibit _______ effect 13. Magnetostriction consists in the changing of length of a ferromagnetic material subjected to a ________ field. 14. Ultrasonic waves show negligible diffraction due to _____wavelength. 1 is the formula for finding frequency of ________. 15. f = 2Π LC III. True/False Statements: 16. The reverberation time should be neither too large nor too small.

(True/False)

17. Carpets, curtains are used to absorb the sound in a hall.

(True/False)

18. The walls of a hall built for music corners should reflect sound.

(True/False) Contd……(3)

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19. The absorption coefficient usually measured in units of open window. (True/False) 20. The prevention of the transmission of noise inside or outside the hall is known as sound insulation. (True/False) -o0o-

H.TNO:________________________ Code No: 07A1BS03

Set No. 3

I B.Tech. Regular I Mid Term (Objective) Online Examinations, Dec. - 2008 ENGINEERING PHYSICS Time: 20 (Min.)

Max Marks: 20 Answer All Questions

All Questions Carry Equal Marks ***** I. Multiple choice Questions: 1. The constructive interference the resultant amplitude will be 1] Difference of individual amplitude 2] Sum of individual amplitudes 3] Multiplication of individual amplitudes 4] Division of individual amplitudes

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2. Young’s double slit experiment is based on the principle of 1] Division of amplitude 2] Division of light rays 3] Division of wave front 4] Division of particles

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3. Thickness of very thin films can be found by the technique 1] Dispersion 2] Interference 3] Polarization 4] Diffraction

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4. The grating spectrum is due to 1] Diffraction 2] Polarization 3] Interference 4] Refraction

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5. In diffraction phenomena all the maxima are of 1] Zero intensity 2] Constant intensity 3] Same intensity 4] Different intensity

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6. The Fraunhofer diffraction patterns were found in 1] Optical instruments 2] Electrical instruments 3] Musical instruments 4] Travelling microscope

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7. In grating the exact position of principal maxima in diffraction pattern depends on [ ] 1] Energy 2] Intensity 3] Wavelength 4] Amplitude Contd…..(2)

:2: 8. In diffraction grating, the condition for principal maxima is 1] d sin θ = nλ 2] sin θ = nλ 3] e sin θ = nλ 4] (e +d) sin θ = nλ

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9. When ordinary light is incident on a polished surface, it undergoes [ 1] Polarization 2] Diffraction 3] Interference 4] Reflection

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10. Ordinary ray in double refraction follows laws of 1] Reflection 2] Polarization 3] Refraction 4] Diffraction

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II. Fill in the Blanks: 11.Ultrasonic waves are also called ________. 12.The ultrasonic generators arte based on the ______ principle 13.The material that exhibit periodic changes in their mechanical dimensions and variations of high frequency constitute _____ waves. 14.The depth of an ocean is d = _______ 15.Supersonic plane flies with the speed ______ than the speed of sound. III. True/False Statements: 16.The reverberation time is proportional to volume. 17.The reverberation time, T= T =

0.165V A

(True/False) (True/False)

18.If reflected sound arrives to audience earlier than direct sound, then loudness remains same 19.Open window unit is also called as sabines.

(True/False) (True/False)

20. If there are extensive reflecting surfaces of the wall, then there will be formation of stationary waves. (True/False) -o0o-

H.TNO:________________________ Code No: 07A1BS03

Set No. 4

I B.Tech. Regular I Mid Term (Objective) Online Examinations, Dec. - 2008 ENGINEERING PHYSICS Time: 20 (Min.)

Max Marks: 20 Answer All Questions

All Questions Carry Equal Marks ***** I. Multiple choice Questions: 1. The modification of light intensity will happen in this phenomena 1) Interference 2) Reflection 3) Polarization 4) Diffraction

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2. Young’s double slit experiment establishes the fact that 1) Light consists of waves 2) Light consists of particles 3) Conservation of energy 4) Redistribution of energy

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3. Two sources of light are said to be coherent when the waves produced are 1) Equal wavelength [ ] 2) Equal amplitude 3) Equal wavelength and constant phase difference 4) Equal amplitudes and equal wavelengths 4. If the air film in Newton’s ring apparatus is replaced by an oil film, the radius of the ring [ ] 1) Increases 2) Decreases 3) Remains same 4) No rings 5. Fresnel diffraction occurs due to [ 1) Interference of secondary waves originated from the same wave front 2) Interference of primary wave originated from the source 3) Interference of polarized light 4) Rectilinear propagation of light

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6. If the slit in Fraunhofer single slit becomes narrower, then the central maxima becomes [ ] 1) Zero 2) Narrow 3) Wider 4) Same as before 7. If 1) 2) 3) 4)

the light transmits through grating, then such type of grating is called Transmission grating [ ] Diffraction grating Absorption grating Reflection grating Contd….(2)

:2: 8. Dispersive power of the grating 1] 2] 3] 4]

dθ = dλ

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n (e + d ) cos θ n (e − d ) cos θ n (e + d cos θ ) n (d + e cos θ )

9. Longitudinal waves do now exhibit 1) Refraction 2) Polarization 3) Interference 4) Diffraction 10. In which crystal the only extraordinary ray is transmitted 1) Nicol 2) Alum 3) Nacl 4) Quartz II. Fill in the Blanks:

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11. Ultrasonic waves are having frequencies ______ 12. When a rod of nickel is placed in a magnetic field parallel to its length the contraction takes place. This phenomena is due to ________ 13. Ultrasonic waves moves with the _____ velocity as sound waves. 14. Quartz crystal is used in _______ method to produce ultrasonic 15. The velocity of sound in air is not affected by change in ______ pressure. III. True/False Statements: 16. The walls of a hall built for music corners should absorb sound

(True/False)

17. If reflected sound arrives to audience earlier than direct sound, then loudness increases 18. The reverberation time

(True/False) T=

165V A

(True/False)

19. An open window behaves as a perfect absorber.

(True/False)

20. The structural noise can be reduced by hard floor finish

(True/False)

-o0o-