### PH6151 CHE 2marks

Anna University Regulation 2013 Computer Science & Engineering (CSE) PH6151 CHE 2marks & 16marks for all 5 units are provided below. Download link for CSE 1st SEM PH6151 ENGINEERING PHYSICS Short answers, Question Bank are listed down for students to make perfect utilization and score maximum marks with our study materials.

PH6151  ENGINEERING PHYSICS QUESTION BANK UNIT-IV 2-marks
PART A
1. What is a sound?
Sound is a sensation of waves with frequency of 20 Hz to 20 kHz which are audible to our human ears.
2. Draw the wave forms of music and noise.
Musical waveform Noise waveform
3. Define decibel. The intensity level (L) of sound is expressed in bels. Comparatively bel is a large unit, so decibel (db) is being used for the level of convenience. 1 bel = 10 decibel
4. Define Sabine’s formula. Sabine defined a formula for the reverberation time as, the time taken by the sound intensity to fall to the one millionth of its original intensity after the source stopped the sound production.
5. What is reverberation? The persistence or prolongation of sound in a hall even though the sound source is stopped is called reverberation. 6. What is reverberation time?(May 2009) The time taken by the sound wave to fall below the minimum audibility level after the source is stopped is called reverberation time.
7. Define sound absorption coefficient of material.(Dec 2014) It is defined as the inverse of the area of the sound absorbing materials which absorbs the same amount of sound as that of 1m2 of an open window. It is measured in OWU or Sabine.
8. What are the factors affecting acoustic quality of a building.(June 2012) The following factors are affecting the acoustics of a buildings/ hall/auditorium (i) Reverberation & reverberation time, (ii) Loudness, (iii) Focussing & interference effects, (iv) Echo, (v) Echelon effect, (vi) Resonance, and (vii) Noise.
9. How to control reverberation in a hall? Reverberation time can be reduced by installing sound absorbing materials in placing appropriate places like providing windows and openings, arranging full capacity of audience , completely covering the floor with carpets, covering the ceilings and walls in the fabricating two fibre boards, heavy curtains with folds and decorating the walls with drawing boards, picture boards.

10. Name the different types of noises. The different types of noises are(i) Air-Borne noise (ii) Structure borne noise (iii) Inside noise.
11. StateWeber-Fechner law.(Jan 2014) Weber-Fechner law states that, the loudness is directly proportional to the logarithm of intensity. L α log10I L = k log10 I , where k is a constant.
12. Define loudness. It is defined as the measure of the magnitude of sensation produced in the ear.
13. Explain the effect of echo in an auditorium. If sound get scattered by wall, instead of refection, echoes may be created. If the time interval between the direct sound and the reflected sound is less than 1/15 of a second, the reflected sound reach the audience later than the direct sound.
14. What is Echelon effect? A new different sound is produced by repetitive echoes is called as Echelon effect.Any regular reflecting surface like stair case may create this effect. It spoils the quality of original sound.
15. How are sound waves classified? • Infrasonic: Sound waves having frequency < 20 Hz. • Audible sound: Sound waves having frequency in between 20 Hz and 20 kHz. • Ultrasonics: Sound waves having frequency > 20 Hz.

PH6151 CHE Unit 1 2marks & 16marks  – Download Here

PH6151 CHE Unit 2 2marks & 16marks Part A – Download Here
PH6151 CHE Unit 2 2marks & 16marks Part B – Download Here
PH6151 CHE Unit 2 2marks & 16marks Part C  Download Here

PH6151 CHE Unit 3 2marks & 16marks Part A – Download Here
PH6151 CHE Unit 3 2marks & 16marks Part B – Download Here

PH6151 CHE Unit 4 2marks & 16marks Part A – Download Here

PH6151 CHE Unit 5 2marks & 16marks Part A – Download Here
PH6151 CHE Unit 5 2marks & 16marks Part B – Download Here

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