Waves MCQ: Definition and Concept

Ans. b) Elephant

Explanation: frequency can be divided into 3 classes -:

Audible Sound Waves

• The range of this wave is 20Hz – 20,000 Hz
• This type of wave can be detected by humans.

Ultrasonic Waves

• The range of this wave is more than 20,000Hz
• Humans cannot notice the ultrasound waves.

Infrasonic Waves

• The range of this wave is less than 20,000 Hz
• Humans cannot notice it as well.

After this research, we have found that infrasonic sound is produced by elephants.

Elephants have the genetics to communicate by using very low-frequency sound with noise below the range of human hearing.

Ans. d) Magnetic Wave

Explanation:

• X rays and ionizing radiation are not involved in MRI. It is distinguished with CT Scan, PET scan, etc.
• MRI scanners function with the help of magnetic field gradients and radio waves to bring forth images of the organ.

Ans. a) Vacuum

Explanation:

• The sound wave cannot pass through the vacuum. It is a sphere without any air.
• Sound wave is a mechanical wave because of which sound cannot pass or travel through a medium, and no kind of vibrations can work in it, that’s why it can’t travel or pass through a vacuum.
• Sound waves can pass through solid, liquid, and gas.

Ans. b) Transverse Wave

Explanation: There are 2 types of waves in the following chapter

Longitudinal Wave - “ if the particles of the medium vibrate in the direction of propagation of the wave, the wave is known as Longitudinal wave.”

Ex – Wave on springs.

Transverse Wave – “if the particles of the medium vibrate perpendicular to the direction of propagation of a wave, it is known as a transverse wave.

Ex- Wave on the surface of the water."

Ans. c) Violet

Explanation:

• Direction of the wavelength is measured
• Spectrum of visible light has various colors with different wavelengths.
• The wavelength is longer and the frequency is lower and, vice versa, the wavelength is shorter and the frequency is higher.

Ans. c) 1 cm-1

Explanation:

y =(5mm) sin [( 1 cm-1) x- (60s-1)t]

= y = A sin (kx – wt = y = (5mm) sin [(1cm-1)x – (60s-1)t]

= K = 1cm-1

Ans. a) Metre/sound

Explanation: Speed = distance/time

• The speed of sound is described as the distance traveled per unit of time by any sound.
• The dynamic propagation of sound waves defines the speed of sound.
• The speed of sound is used in various fields in physics.
• The speed of sound waves is described in an elastic medium

Ans. d) Wavelength of the wave

Explanation: It signifies the wavelength sign and is measured in meters.

Ans. a) Progressive waves

Explanation:

• A wave that can travel constantly in a medium in the same direction without any change in its amplitude is known as a progressive wave.
• Progressive waves are also known as traveling waves.
• Ex – when the bell rings and vibrates, the waves never return.

Ans. b) bulk modulus of elasticity

Explanation:

• When the longitudinal sound waves are in solid existence with a velocity and wave impedance which is dependent on the material’s density and its rigidity.
• It is described by the material’s bulk modulus.

Ans. b) Minimum friction

Explanation: the friction force amongst the matter of the medium should be insignificantly small, they continue oscillating for a long time and the wave travels a long distance through the medium.