Sound

Total Questions: 56

1. In Stethoscope, the sound of the patient's heartbeat reaches the doctor's ears by: [R.A.S./R.T.S (PRE) 2021]

(a) Multiple diffraction of sound
(b) Multiple reflection of sound
(c) Polarisation of sound
(d) Multiple refraction of sound

Correct Answer: (b) Multiple reflection of sound
Note:

Stethoscopes work by the principle of multiple reflection of sound. When a doctor or nurse places a stethoscope diaphragm on a patient's chest, sound waves traveling through the patient's body cause the flat surface of the diaphragm to vibrate and because the vibrating object is attached to a tube, the sound waves are channeled in a specific direction. Each wave bounces, or reflects, off the inside walls of the rubber tube, a process called multiple reflection. In this way, each wave, in succession, reaches the eartips, or rubber nubs on the ends of the device, and finally the listener's eardrums.

2. Which one of the following is the effect of the light of supersonic jet ? [M.P.P.C.S.(PRE) 1993]

(a) air pollution
(b) eye disease
(c) depletion in ozone layer
(d) none of these

Correct Answer: (c) depletion in ozone layer
Note:

Jet engine are responsible for depletion of ozone.Flying at stratosphere height they emits nitrogen oxide which has the potential to destroy significant quantities of ozone in the stratosphere.

3. Assertion (A) : A jet aircraft moving at mach number equal to travel faster at an altitude of 15 km than while at mach number equal to 1 near sea level. [I.A.S. (PRE) 2007]

Reason (R) :The velocity of sound depends on the temperature of the surrounding medium.
code :

(a) both (A) and (R) are true and (R) is the correct explanation of (A)
(b) both (A) and (R) are true and (R) is not the correct explanation of (A)
(c) (A) is true but (R) is false
(d) (A) is false but (R) is true

Correct Answer: (d) (A) is false but (R) is true
Note:

Speed of supersonic bodies is indicated by the mach number the mach number of an airplane is the ratio of the speed of the body of sound in a particular medium usually the atmosphere of the earth as we know that the speed of sound increase with the increase of temperature the speed of sound at higher altitude (15 km above the sea level ) decreases due to decreases in temperature thus the statement (1) is false .The velocity of a sound wave travelling through the air does not very with the air pressure but depends on the temperature of the air.Thus the reason (R) is the correct

4. Decibel is used to measure the : [M.P.P.S.C (Pre) 2005]

(a) hemoglobin in blood
(b) sugar in urine
(c) sound in atmosphere
(d) particle in air

Correct Answer: (c) sound in atmosphere
Note:

Decibel (DB) is used to measure the intensity of sound in atmosphere.

5. Decibel unit is used to measure : [U.P.P.C.S.(MAINS) 2011]

(a) light intensity
(b) sound of intensity
(c) magnitude of the earthquake
(d) none of the above

Correct Answer: (b) sound of intensity
Note:

Decibel (DB) is used to measure the intensity of sound in atmosphere.

6. Decibel unit is used to measure : [Uttarakhand Lower Sub.(PRE) 2010]

(a) speed of the light
(b) intensity of heat
(c) intensity of sound
(d) radioactive frequency

Correct Answer: (c) intensity of sound
Note:

Decibel (DB) is used to measure the intensity of sound in atmosphere.

7. What is the decibel level of sound produced by two persons in conversation ? [R.A.S./R.T.S (PRE) 2003]

(a) about 5 decibel
(b) about 10 decibel
(c) about 30 decibel
(d) about 100 decibel

Correct Answer: (c) about 30 decibel
Note:

The intensity of sound is measured in decibel

source of sound	intensity (in decibel)
whisper	15-20
normal conversation	30-60
anger conversation	70-80
truck motorcycle	90-95
instrument factory	100-110
jet plane	140-150

8. A noise level of 100 decibel would correspond to : [I.A.S. (PRE) 2000]

(a) just audible sound
(b) ordinary sound
(c) sound from a noisy street
(d) noise from the machine shop

Correct Answer: (d) noise from the machine shop
Note:

The intensity of sound is measured in decibel

source of sound	intensity (in decibel)
whisper	15-20
normal conversation	30-60
anger conversation	70-80
truck motorcycle	90-95
instrument factory	100-110
jet plane	140-150

9. Which of the following represent the decibel level of rustling of tree leaves in normal circumstance ? [U.P.P.C.S.(pre) 2018]

(a) 10 dB
(b) 20 dB
(c) 60 dB
(d) 100 dB

Correct Answer: (d) 100 dB
Note:

In normal circumstances the decibel level of the rustling of the tree leaves in about 20 decibel . A decibel (dB) is 1/10 of a bel which is a unit of sound intensity named in the honour of Alexander Graham Bell.

10. As per the WHO the safe noise level for a city is - [U.P.P.C.S.(MAINS) 2010]

(a) 45 dB
(b) 50 dB
(c) 55 dB
(d) 60 dB

Correct Answer: (a) 45 dB
Note:

As per the WHO the safe noise level for a city is 45 decibel (dB).

12 3 4 5 6 Next »

Sound

Sound

1. In Stethoscope, the sound of the patient's heartbeat reaches the doctor's ears by: [R.A.S./R.T.S (PRE) 2021]

2. Which one of the following is the effect of the light of supersonic jet ? [M.P.P.C.S.(PRE) 1993]

3. Assertion (A) : A jet aircraft moving at mach number equal to travel faster at an altitude of 15 km than while at mach number equal to 1 near sea level. [I.A.S. (PRE) 2007]

4. Decibel is used to measure the : [M.P.P.S.C (Pre) 2005]

5. Decibel unit is used to measure : [U.P.P.C.S.(MAINS) 2011]

6. Decibel unit is used to measure : [Uttarakhand Lower Sub.(PRE) 2010]

7. What is the decibel level of sound produced by two persons in conversation ? [R.A.S./R.T.S (PRE) 2003]

8. A noise level of 100 decibel would correspond to : [I.A.S. (PRE) 2000]

9. Which of the following represent the decibel level of rustling of tree leaves in normal circumstance ? [U.P.P.C.S.(pre) 2018]

10. As per the WHO the safe noise level for a city is - [U.P.P.C.S.(MAINS) 2010]

Related Posts

Leave a Reply Cancel reply

Cancel reply