Question 1

Main sources of noise pollution are

Accepted Answer

Transportation equipment and heavy machinery are major sources of noise pollution, contributing significantly to the overall noise levels in urban and industrial areas.

Question 2

The sound can travel in air when:

Accepted Answer

Sound travels in air (or any medium) when a disturbance created by the vibration of an object causes the particles of the medium to vibrate and this disturbance travels through the medium, not the particles themselves moving from one place to another. Moisture in the atmosphere is not a requirement for sound to travel.

Question 3

White noise is random noise that has a audible frequency rangefrom

Accepted Answer

White noise contains all frequencies that are audible to humans, which typically range from 20 Hz to 20 kHz.

Question 4

Which among the following has a constant power spectral density over a wide frequency range?

Accepted Answer

White noise has a constant power spectral density across a wide range of frequencies, meaning it has equal intensity at different frequencies, giving it a "flat" spectrum.

Question 5

Which is correct option for ear protection equipment?

Accepted Answer

Ear defenders and ear plugs are specifically designed for ear protection, unlike headphones or cotton.

Question 6

The technique or method to absorb undesirable sounds by soft and porous

Accepted Answer

Acoustic protection involves using materials and techniques to absorb or dampen undesirable sounds, making environments more acoustically pleasant and preventing noise pollution.

Question 7

When sound interacts with materials and boundaries, it displays all the

Accepted Answer

Sound is a type of energy that travels through materials as waves, not as heat, light, or electricity.

Question 8

Soft materials absorb a large amount of

Accepted Answer

Soft materials are particularly effective at absorbing sound energy, which helps in reducing noise levels. They are used in acoustic treatments to dampen sound.

Question 9

Reflection coefficient (?) is the rario of intensity of sound ______________.

Accepted Answer

The reflection coefficient for sound is defined as the ratio of the intensity of the reflected sound to the intensity of the incident sound.

Question 10

Absorption coefficient (?) is the rario of intensity of sound ______________.

Accepted Answer

The answer of Absorption coefficient (?) is the rario of...

Question 11

Which best describe the sound wave?

Accepted Answer

The answer of Which best describe the sound wave?
...

Question 12

Which of the following can not travel through a vacuum?

Accepted Answer

Sound waves require a medium (solid, liquid, or gas) to travel through and cannot propagate through a vacuum, unlike electromagnetic waves, radio waves, and light waves, which can travel through a vacuum.

Question 13

Sound wave has two main characteristics which are

Accepted Answer

Pitch and loudness are the two main characteristics of sound waves. Pitch is determined by the frequency of the sound wave, while loudness is determined by its amplitude.

Question 14

When waves bend away from straight lines of travel, it is called

Accepted Answer

The answer of When waves bend away from straight lines...

Question 15

_________ is the sound power measured over the area upon which is received.

Accepted Answer

Sound intensity is defined as the sound power per unit area, which is a measure of the energy flow of sound waves through a given area.

Question 16

It is an audio transducer that converts acoustic pressure in air into its equivalent electrical impulses

Accepted Answer

Microphones are designed to convert sound waves (acoustic pressure) into electrical signals, making them the correct answer. Loudspeakers do the opposite, converting electrical signals into sound waves. Amplifiers increase the power of signals, and baffles are used to prevent direct sound paths in audio applications, neither converting acoustic pressure into electrical impulses.

Question 17

_________ is a pressure type microphone with permanent coil as a transducing element.

Accepted Answer

Dynamic microphones use a diaphragm/voice coil/magnet assembly as the transducing element, where sound waves cause the diaphragm to move, inducing a current in the coil. This principle is based on electromagnetic induction, hence the term "dynamic."

Question 18

A capacitor stores energy in the form of an electrostatic field is a ______.

Accepted Answer

Condenser microphones use a capacitor to convert acoustic energy into electrical energy. The term "condenser" is an older term for capacitor, hence the name.

Question 19

A microphone that uses the piezoelectric effect

Accepted Answer

Crystal microphones use the piezoelectric effect to convert sound into an electrical signal.

Question 20

It describes the output of a microphone over a range of frequencies.

Accepted Answer

Frequency response describes how a microphone reacts to different frequencies of sound, indicating its output over a range of frequencies.

Quiz 7: Understanding Sound and Noise Pollution