# Noise Pollution MCQ – Environmental Engineering

41. The level at which the prolonged exposure of noise can cause deafness

1. 20 dB
2. 85 dB
3. 10 dB
4. 35 dB

42. The reference pressure used in the determination of sound pressure level is

1. 20 dB
2. 20 μPa
3. 10 dB
4. 10 μPa

43. Allowed noise level in residential areas during day time in India

1. 55 dB
2. 25 dB
3. 00 dB
4. 75 dB

44. Acceptable noise level in dB for auditorium is

1. 25 to 30
2. 40 to 45
3. 35 to 40
4. 45 to 55

45. If threshold of hearing is 0.0002 bar, what will be the SPL in decibels if sound pressure is 200 μ bar?

1. 110
2. 120
3. 130
4. 140

46. The resultant sound pressure level of two sound sources each having a sound pressure level of 50 dB is

1. 100 dB
2. 120 dB
3. 15.5 dB
4. 53 dB

47. The frequency for audible sound (in Hz) ranges from

1. 2-2000
2. 1000-10000
3. 16-20000
4. 40-40000

48. Two sound sources are emitting sound simultaneously with sound levels of 60 dB and 70 dB. What will be the resultant sound level?

1. 80.8 dB
2. 70.4 dB
3. 75.6 dB
4. 130 dB

49. What is the resultant noise level generated simultaneously from two sources with same intensity of 90 dB respectively?

1. 95 dB
2. 90 dB
3. 91 dB
4. 93 dB

50. The permitted noise level in a silent zone during day time and night time are respectively

1. 55 dB and 50 dB
2. 70 dB and 60 dB
3. 50 dB and 40 dB
4. 65 dB and 55 dB