Unit 12: Electromagnetic Spectrum - Physics II - For Class X (Science Group) - MCQs, Fill in the blanks and Concept Map

Go To Index
Unit 12: Electromagnetic Spectrum
Physics II
For Class X (Science Group)

• MCQs From Text Book Exercise
• More MCQs
• Fill In The Blanks
• Abbreviations Or Symbols
• Units
• Concept Map

Multiple Choice Questions (MCQs)
From Text Book Exercise

Choose the correct answer from the following choices:
✓ 1. The waves that have maximum penetrating power to treat tumours are:
(a) ultraviolet radiation
(b) microwaves
(c) gamma-rays ✔
(d) radio waves

2. The electromagnetic rays used in radiotherapy to destroy cancer cells are:
(a) infrared rays
(b) visible rays
(c) x - rays ✔
(d) ultraviolet rays

3. The velocity of light in a diamond is:
(whereas the refractive index of a diamond with respect to vacuum is 2.5)
(a) 1.2 x 10⁸ m/s ✔
(b) 5 x 10⁸ m/s
(c) 1.2 x 10¹⁰ m/s
(d) 2.5 x 10⁸ m/s

4. The group containing only electromagnetic waves is:
(a) Light waves, radio waves, Microwaves ✔
(b) Light waves, Radio waves, Sound waves
(c) Light waves, Sound waves, Microwaves
(d) Radio waves, Sound waves, Microwaves

5. The list that shows electromagnetic waves in order of increasing wavelength is:
(a) Microwaves, X-rays, Gamma-rays
(b) Microwaves, Gamma-rays, X-rays
(c) X-rays, Gamma-rays, Microwaves
(d) Gamma-rays, X-rays, Microwaves ✔

6. The type of electromagnetic wave used in security scanners at night is:
(a) infra-red ✔
(b) microwaves
(c) radio waves
(d) X-ray

7. A narrow beam of white light passes from air into the glass and is refracted. The wave characteristic remains unchanged in its:
(a) direction
(b) frequency ✔
(c) speed
(d) wavelength

8. The type of waves that are used in the television remote controllers:
(a) Radio waves
(b) Infra-red waves ✔
(c) Ultra-violet waves
(d) Visible light

9. The colour that is least deviated by a prism:
(a) Violet ray
(b) Green ray
(c) Red ray ✔
(d) Yellow-ray

10. The optical phenomenon in which the splitting of white light into seven distinct colours occur is called:
(a) refraction
(b) reflection
(c) dispersion ✔
(d) diffraction

GO TO TOP

More Multiple Choice Questions (MCQs)
From Chapter

11. The white light consists of:
(a) 5 colours
(b) 6 colours
(c) 7 colours ✔
(d) 8 colours

12. This colour has a maximum speed in the glass prism, with the slightest deviation.
(a) Violet
(b) Blue
(c) Green
(d) Red ✔

13. This colour has minimum speed, which with most deviation.
(a) Violet ✔
(b) Blue
(c) Green
(d) Red

14. This colour has its own refracted path in the air and becomes distinct on the spectrum.
(a) Red
(b) Violet ✔
(c) Yellow
(d) Orange

15. It has the highest wavelength of all the colours.
(a) Red ✔
(b) Violet
(c) Yellow
(d) Orange

16. Which statement is TRUE about the red light?
(a) The air molecules least scatter it
(b) It can travel the longest distance
(c) It penetrates through rain mist, and fog
(d) All of them ✔

17. Vibrating atoms in a hot, glowing bulb filament emit:
(a) infrared and visible light ✔
(b) ultraviolet and visible light
(c) microwave and visible light
(d) radio waves and visible light

18. Electromagnetic waves are:
(a) longitudinal waves
(b) transverse waves ✔
(c) mechanical waves
(d) Both 'a' and 'c'

19. All electromagnetic waves travel through space or vacuum at the same speed of:
(a) 300000 km/s
(b) 3 x 10⁸ m/s
(c) Both 'a' & 'b' ✔
(d) None of them

20. Light-year is a unit of:
(a) distance ✔
(b) time
(c) speed
(d) None of these

21. The direction of wave motion of electromagnetic waves is:
(a) perpendicular to electric field
(b) perpendicular to magnetic field
(c) perpendicular to electric eectric & magnetic fields ✔
(d) parallel to electic & netic fields

22. Which of these electromagnetic waves has a high frequency?
(a) X-rays
(b) Gamma rays
(c) Both 'a' & 'b' ✔
(d) None of these

23. It has the longest wavelength in the electromagnetic spectrum.
(a) X-rays
(b) Gamma rays
(c) Microwaves
(d) Radio waves ✔

24. The list that shows electromagnetic waves from the lowest to the highest frequency is:
(a) radio waves, microwaves, visible light ✔
(b) visible light, infrared radiations, x-rays
(c) gamma rays, x-rays, visible light
(d) visible light, radio waves, ultraviolet radiations

25. Stars are natural transmitters of:
(a) microwaves
(b) radio waves ✔
(c) ultraviolet rays
(d) x-rays

26. The human body also gives out:
(a) microwaves
(b) radio waves
(c) infrared radiations ✔
(d) x-rays

27. It has been used for security purposes, particularly in military technology.
(a) Infrared waves ✔
(b) Microwaves
(c) Radio waves
(d) Ultraviolet rays

28. Ultraviolet radiation is further divided into:
(a) two bands
(b) three bands ✔
(c) four bands
(d) five bands

29. This kind of lamp is used in sunbeds for artificial tanning.
(a) Mierowave
(b) Infrared
(c) Gamma rays
(d) Ultraviolet ✔

30. They are produced when fast-moving electrons lose their energy quickly.
(a) Microwaves
(b) Infrared
(c) x-rays ✔
(d) gamma rays

31. They are highly penetrating that can pass through flesh but not bones.
(a) The long-wavelength x-rays
(b) The low-frequency x-rays
(c) Both 'a' & 'b' ✔
(d) None of them

32. It uses a series of low-frequency X-rays and a computer to produce a 3D image of soft tissues and bones.
(a) Computed Tomography (CT) scan ✔
(b) Radiation Therapy
(c) Industrial radiography
(d) x-rays

33. It is a cancer treatment that uses controlled doses of high-frequency x-rays to kill cancerous cells and shrink tumours.
(a) Computed Tomography (CT) scan
(b) Radiation Therapy ✔
(c) Industrial radiography
(d) x-rays

34. They are produced when the nuclei of unstable atoms decay into a stable nucleus or lose energy.
(a) Microwave
(b) Infrared
(c) Gamma rays ✔
(d) Ultraviolet

35. Which of the following has a minimum wavelength?
(a) Gamma rays ✔
(b) Blue light
(c) Infrared rays
(d) Microwave

36. Which among the following has the maximum penetrating power?
(a) Radio waves
(b) Microwaves
(c) Ultraviolet radiation
(d) Gamma rays ✔

37. The structure of solids is investigated by using:
(a) microwaves
(b) gamma rays
(c) x-rays ✔
(d) infrared rays

38. The ultra-high frequency band of radio waves in the electromagnetic wave is used as in:
(a) television
(b) cellular phone communication ✔
(c) commercial FM radio
(d) Both 'a' and 'b'

39. The waves used by artificial satellites for communication are:
(a) microwaves ✔
(b) infrared waves
(c) radio waves
(d) x-rays

40. Which of the following electromagnetic waves is used in medicine to destroy cancer cells?<br> (a) Infrared rays
(b) Visible rays
(c) Gamma rays ✔
(d) Ultraviolet rays

41. Which of the following has a minimum wavelength?
(a) Blue light
(b) Gamma rays ✔
(c) Infrared rays
(d) Microwave

42. Waves in decreasing order of their wavelength are:
(a) x-rays, infrared rays, visible rays, radio waves
(b) radio waves, visible rays, infrared rays, x-rays
(c) radio waves, infrared rays, visible rays, x-rays ✔
(d) radio waves, ultraviolet rays, visible rays, x-rays

43. Which of the following statement is false for the properties of'electromagnetic waves?
(a) Both electric and magnetic field vectors attain the maxima and minima at the same place and same time
(b) The energy in-electromagnetic waves is divided equally between electric and magnetic field Vectors
(c) Both electric and magnetic field vectors are parallel to each other and perpendicular to the direction of propagation of the wave ✔
(d) These waves do not require any material medium for propagation

44. Which one of the following has the shortest wavelength?
(a) Infrared rays
(b) Ultraviolet rays
(c) Microwaves
(d) Gamma rays ✔

45. Select the wrong statement. Electromagnetic waves:
(a) are transverse in nature
(b) travel in free space at a speed of light
(c) are produced by accelerating charges
(d) travel in all media with the same speed ✔

46. Select the correct statement(s) from the following:
(i) Wavelength of microwaves is greater than that of ultraviolet rays.
(ii) The wavelength of infrared rays is lesser than that of ultraviolet rays.
(iii) The wavelength of microwaves is lesser than that of infrared rays.
(iv) Gamma-ray has the shortest wavelength in the electromagnetic spectrum
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv) ✔

47. Choose the electromagnetic wave that is the most dangerous to humans.
(a) Radio waves
(b) Ultraviolet rays ✔
(c) Microwaves
(d) Infrared

48. What are the two colours that emerge from Prism's two extreme ends?
(a) Blue and Green
(b) Yellow and Orange
(c) Red and Orange
(d) Violet and Red ✔

49. In a vacuum, all electromagnetic spectrum components have the same:
(a) frequency
(b) wavelength
(c) velocity ✔
(d) energy

GO TO TOP

Fill In The Blanks

1. A prism is a transparent block of glass that produces dispersion.
2. The prism refracts the narrow beam of white light that cause the spectrum of colors.
3. Dispersion of white light is splitting white light into its constituent colors.
4. Every wavelength of light changes speed and direction accordingly when it passes through another transparent medium.
5. Dispersion of white light in a water droplet is the combination and total internal reflection.
6. The electromagnetic spectrum is the range of all electromagnetic waves or radiations.
7. The electromagnetic waves are transverse.
8. Oscillations of electric and magnetic fields of electromagnetic waves are perpendicular to energy transfer.
9. All electromagnetic waves travel through a vacuum at the same speed of c = 3 x 10⁸ m.s^-1.
10. The electromagnetic waves travel through a transparent medium.
11. electromagnetic waves slow down when traveling through other denser mediums.
12. The electromagnetic waves obey the laws of reflection, refraction, and diffraction.
13. The electromagnetic spectrum, from the longest to shortest wavelength, includes all radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays.
14. Radio waves have the longest wavelengths in the electromagnetic spectrum.
15. Microwaves have wavelengths in the micrometer range.
16. Infra-red is used in wireless remote controllers.
17. Intruder alarms use infrared radiations that detect the changing pattern emitted by a warm body at night.
18. The white light is a small portion of the electromagnetic spectrum that is only visible to our eyes.
19. Optical fibers work on the principle of total internal reflection.
20. Optical fibers are widely used in communications technology.
21. An endoscope is a medical device of optical fibers that enables doctors to see abnormalities in organs inside a human body.
22. Ultraviolet radiations are commonly used in sun beads, fluorescence, and sterilization.
23. X-rays are used in CT scans for medical imaging and radiotherapy to treat cancer.
24. The cyberknife uses gamma rays in radiosu cancerous cells.
25. PET uses the gamma rays in medical imaging to produce functional three-dimensional images of abnormal tissues or tumors.

GO TO TOP

Abbreviations OR Symbols

• c stands for Speed
• CT stands for Computed Tomography
• EM stands for Electromagnetic
• EMR stands for Electromagnetic radiation
• f stands for Frequency
• hi-fi stands for High Fidelity
• Hz stands for Hertz
• IR stands for Infra Red
• MRI stands for Magnetic Resonance Imaging
• PET stands for Positron Emission Tomography
• pm stands for picometer
• TV stands for Television
• UHF stands for Ultra High Frequency
• UV stands for Ultraviolet
• VHF stands for Very High Frequency
• VIBGYOR stands for Violet, Indigo, Blue, Green, Yellow, Orange, Red
• 𝞴 stands for Wavelength

GO TO TOP

Units

• Unit of Frequency is Hertz (Hz).
• Unit of Refractive Index has No unit because its ratio of similar quantities.
• Unit of Speed are kilometer per second (km/s) OR Meter per second (m/s).
  => (1km = 1000 m)
• Unit of Wavelength are meter (m) OR Nanometer (nm) OR Picometer (pm)
  => (1 nanometer = 10^-9 mater)

GO TO TOP

Concept Map

GO TO TOP

Unit 11: Sound - Physics II - For Class X (Science Group) - MCQs, Fill in the blanks and Concept Map

Go To Index
Unit 11: Sound
Physics II
For Class X (Science Group)

• MCQs From Text Book Exercise
• More MCQs
• Fill In The Blanks
• Abbreviations Or Symbols
• Units
• Concept Map

Multiple Choice Questions (MCQs)
From Text Book Exercise

Choose the correct answer from the following choices:
1. Sound is a form of:
(a) electrical energy
(b) mechanical energy ✔
(c) thermal energy
(d) chemical energy

2. Audible frequencies range that a normal human ear can detect is:
(a) 10 Hz and 10 kHz
(b) 20 Hz and 20 kHz ✔
(c) 25 Hz and 25 kHz
(d) 30 Hz and 30 kHz

3. The approximate value of the speed of sound in air at 0°C temperature is:
(a) 332 m/s ✔
(b) 34 m/s
(c) 17 m/s
(d) 680 m/s

4. Sound travels faster in solid as compared to gases because of:
(a) gas molecules are packed loosely
(b) sound does not travel faster through a solid than a gas
(c) solid molecules are packed tightly ✔
(d) gas molecules move faster.

5. The two factors that affect the speed of sound in the air are:
(a) humidity and volume of the air
(b) temperature and mass of the air
(c) volume and mass of the air
(d) temperature and humidity of the air ✔

6. The separation between two consecutive compressions of the sound wave is called:
(a) time period
(b) amplitude
(c) frequency
(d) wavelength ✔

7. The order of speed of the sound in different mediums from faster to slowest is:
(a) Gas → Liquid → Solid
(b) Liquid → Solid → Gas
(c) Solid → Liquid → Gas ✔
(d) Gas → Solid → Liquid

8. Ultrasound has several uses in medicine and industry. Which one has the use of ultrasound?
(a) Absorption
(b) Pre-natal scanning ✔
(c) Dispersion
(d) Measuring humidity of air

9. The cause of the echo is:
(a) absorption
(b) dispersion
(c) reflection ✔
(d) refraction

10. Which types of waves cannot travel through a vacuum?
(a) Sound waves ✔
(b) infra-red radiation
(c) Microwave
(d) X-rays

GO TO TOP

More Multiple Choice Questions (MCQs)
From Chapter

11. Sound waves are:
(a) longitudnal waves ✔
(b) transverse waves
(c) electromagnetic waves
(d) All of these

12. To propagate, sound needs a material medium of:
(a) gases & liquids
(b) gases & solids
(c) liquids & solids
(d) gases. liquids & solids ✔

13. The speed of sound is the same in all mediums." This statement is:
{a) true
-(b) false ✔
(c) sometimes true
(D) depends on conditions

14. The speed of sound depends on the properties such as:
(a) the temperature of the medium
(b) pressure of the medium
(cj the density of the medium
(d) All of them ✔

15. The formula to find the speed of sound at temperature T in the air is:
(a) v = 331 √273K / T
(b) v = 331 √T / 273K ✔
(c) v = 273 √331K / T
(d) v = 273 √T / 331K

16. The speed of sound in air is directly proportional to the square root of the:
(a) absolute temperature ✔
(b) length of the sound column
(c) mass of the al; column
(d) All of these

17. Humidity increases, the density of the air _____ and sound travels _____.
(a) increases, faster
(b) increase. slower
(c) decreases, faster ✔
(d) decreases, slower

18. Loudness depends upon:
(a) wavelength
(b) wevefront
(c) frequency
(d) amplitude ✔

19. Pitch depends upon:
(a) wavelength
(b) wevefront
(c) frequency ✔
(d) amplitude

20. Quality of sound that distinguishes between a shrill and a flat sound is called:
(a) ultrasound
(b) pitch ✔
(c) loudness
(d) quality

21. The SI unit of sound of intensity is:
(a) W
(b) W/m
(c) W/m² ✔
(d) m

22. Over an eight-hour workday, the noise level recommended in most countries is usually:
(a) 85 - 90 dB ✔
(b) 95 -- 100 dB
(c) 105 - 110 dB
(d) 145 - 150 dB

23. At a temperature of 20°C, the speed of sound is:
(a) 300 m/s
(b) 310 m/s
(c) 320 m/s
(d) 340 m/s ✔

24. For hearing clear echoes, the minimum distance of the obstruction from the source of sound should be:
(a) 20 m
(b) 17 m ✔
(c) 14 m
(d) 7 m

25. To hear a clear echo, the time interval between the produced original sounds and the reflected one must be at least:
(a) 0.1 s ✔
(b) 0.5 s
(c) 0.7 s
(d) 1 s

26. The sound with frequencies above the upper limit of the human range of audibility is known as:
(a) infrasound
(b) Ultrasound ✔
(c) Both 'a' & 'b'
(d) None of them

27. Generally, we classify ultrasound as those having frequencies above:
(a) 200 Hz
(b) 2000 Hz
(c) 20,000 Hz ✔
(d) 200,000 Hz

28. Sound with frequencies below the lower limit of the human range of audibility is known as:
(a) Infrasound ✔
(b) Ultrasound
(c) Both 'a' & 'b'
(d) None of them

29. It is extensively used in marine applications:
(a) Echocardiography
(b) Ultrasonography
(c) Transducer
(d) SONAR ✔

30. If a wave completes 20 vibrations in 2.5s, then its frequency is:
(a) 200 Hz
(b) 50 Hz
(c) 20 Hz
(d) 8 Hz ✔

31. On increasing the temperature, the speed of sound in air:
(a) increases ✔
(b) decreases
(c) does not change
(d) becomes zero

32. On what factor does the quality of sound depend?
(a) Wavelength
(b) Waveform ✔
(c) Wave frequency
(d) Wave amplitude

33. Frequency of infrasonic waves is _____ than the frequency of ultrasound waves.
(a) less ✔
(b) more
(c) almost same
(d) none of the above

34. The unit of quantity on which the pitch of the sound depends is:
(a) hertz ✔
(b) metre
(c) metre/second
(d) second

35. Sound waves are produced by:
(a) Linear motion
(b) circular motion
(c) vibrating bodies ✔
(d) transitional motion

36. The loudness of sound varies directly with the vibrating body:
(a) intensity
(b) amplitude ✔
(c) pitch
(d) quality

37. The sensation of sound persists in our brain for about:
(a) 0.001s
(b) 0.2s
(c) 0.1s ✔
(d) lOs

38. Sounds of frequency higher than 20,000 Hz which are inaudible to the normal human ear are called:
(a) noise
(b) freqtiency
(c) ultrasonic ✔
(d) infrasonic

39. The loudness and amplitude of sound vary:
(a) directly ✔
(b) inversely
(c) Not related
(d) proportionally

40. The speed of sound varies with:
(a) humidity only
(b) temperature only
(c) pressure
(d) humidity and temperature ✔

41. Main sources of noise pollution are:
(a) transportation equipment only
(b) heavy machinery only
(c) musical instruments
(d) Transportation equipment and heavy machinery ✔

42. When the frequency of sound increases, the wavelength and period:
(a) becomes negative
(b) remains constant
(c) increases
(d) decreases ✔

43. As compared to air, the speed of sound in liquids and solids is:
(a) lower
(b) faster ✔
(c) equal
(d) zero

44. The reflection of sound is called:
(a) quality
(b) Loudness
(c) pitch
(d) echo ✔
45. Sound waves cannot pass through:
(a) air
(b) vacuum ✔
(c) solid
(d) liquid

46. The technique used to locate underwater depths or locating objects tying deep on the ocean floor is called:
(a) Echocardiography
(b) Ultrasonography
(c) Transducer
(d) SONAR ✔

47. A safe level of noise depends on:
(a) level of noise and exposure to noise
(b) area ✔
(c) pitch
(d) frequency

48. Bats can hear frequencies up to:
(a) 30,000 Hz
(b) 150,000 Hz ✔
(c) 180,000 Hz
(d) 15,000 Hz

GO TO TOP

Fill In The Blanks

1. Sound is the form of energy related to the motion of vibrating molecules.
2. Sound is a longitudinal wave. 3. In longitudinal wave, the direction of vibration of molecules is parallel to the direction of wave motion.
4. Sound wave is comprised of successive compressions and rarefactions in the medium.
5. Compressions are regions where air pressure is slightly higher than surrounding air pressure.
6. Rarefactions are regions where air pressure is slightly lower than the surrounding air pressure.
7. Sound needs a material medium to pass through energy.
8. Sound cannot travel through a vacuum.
9. Sound waves travel at different speeds in different mediums depending on their properties.
10. The speed of sound is faster in solid materials and slower in liquids or gases.
11. Temperature affects the speed of sound in air.
12. Sound travels faster when the temperature of the medium rises.
13. Humidity slightly affects the speed of sound in air.
14. Sound travels faster when the humidity of the air rises.
15. Quality is the characteristic of sound by which we can distinguish between two sounds of the same loudness and pitch.
16. Sounds that are pleasant to our hearing sensations are called musical sounds.
17. Sounds that are unpleasant to our hearing sensations are called noises.
18. The high noise level has harmful effects on human health.
19. The range of audibility is the range of sound frequencies that a person can hear.
20. For tThe normal human ear, the lower limit of audible frequency is 20 Hz, and the upper limit is 20K Hz.
21. Ultrasound is the sound with frequencies above the upper limit of the human range of audibility.
22. The echo is the reflection of the sound after reflection from an obstacle.
23. In industry, ultrasounds can be used to detect cracks, cavities, and flaws in metal and concrete blocks.
24. Sound navigation and ranging (SONAR) is used to measure the depth of sea beds, locate and track submarines at sea, and locate explosive mines below the surface of the water.
25. Echocardiography uses ultrasound to produce the motional images of the heart and its valves.
26. Ultrasonography uses ultrasound to scan soft organs and tissues.

GO TO TOP

Abbreviations OR Symbols

• ℃ stands for Degree Celsius
• dB stands for Decibel
• f stands for Frequency
• Hz stands for Hertz
• kHz stands for Kilohertz
• Km stands for Kilometres
• K stands for Kelvin
• m stands for Meter
• m/s stands for Meter per second
• 𝝆 stands for Density
• 𝛌 stands for Wavelength
• T OR t stands for Time
• s stands for Second
• SI stands for International System of units
• SONAR stands for Sound navigation and ranging
• v OR V stands for Speed
• W stands for Watt
• W/m² stands for Watt per square meter
• ∝ stands for Sign of proportionality

GO TO TOP

Units

• Unit of Distance and Wavelength is Meter and Kilometer
• Unit of Frequency is Hertz
• Unit of Loudness Of sound is Decibel
• Unit of Sound Intensity OR Acoustic intensity is Watt per square meter
• Unit of Speed is Meter per second
• Unit of Temperature are Degree Celsius and Kelvin
• Unit of Time is Second

GO TO TOP

Concept Map

GO TO TOP

Scientific Reasons From All Chapters - Physics For Class X - New Book

Go To Index
Physics For Class IX (Science Group)
SCIENTIFIC REASONS

• By Adamjee Coachin Center
• By admin

Scientific Reasons
By Adamjee Coachin Center

GO TO TOP

Give Reason
By Admin

UNIT 10: GENERAL WAVE PROPERTIES

1. Wave motion transfers energy without moving matter. Justify this statement with an example.
Ans: Waves are means of energy transfer without transfer of matter:
The wave is a disturbance in a medium that transfer energy from one place to another, but waves can not move matter the entire distance.

Example No.1:
When the calm water surface is disturbed by a stone dropping into it, circular water ripples spread out from the point where the stone hits the water. Similarly the continuous disturbance of the water surface by the blasts of the wind caused by a helicopter hovering above creates water waves that move outwards. If we place a cork on the surface of water. We observed that when the waves reaches the cork, it will move up an down along the motion of water particles by getting energy from waves but remain at its position. Thus the disturbance on the water surface moves outwards, carrying energy, and no water, because after the waves pass, the cork on water remains where it was before the wave was produced.

Example No.2:
A tide can travel many kilometres. The water moves up and down - a disturbance that travels in a wave, transferring energy, not matter. Let's consider the example of a buoy bobbing in the ocean. The buoy is moved up and down by the waves that pass by it but doesn't move directionally across the water. Waves transfer energy but not mass. When particles in water become part of a wave, they start to move up or down. This means that kinetic energy (energy of movement) has been transferred to them. As the particles move further away from their normal position (up towards the wave crest or down towards the trough), they slow down. This means that some of their kinetic energy has been converted into potential energy - the energy of particles in a wave oscillates between kinetic and potential energy.
This activity shows that water waves like other waves transfer energy from one place to another without transferring matter, i.e., water.

GO TO TOP

Unit 12: Electromagnetic Spectrum - Important Questions And Answers 2024 By Sir Wasim Ahmad

Go To Index
Physics For Class X
Unit 12: Electromagnetic Spectrum
Question & Answers

By Sir Wasim Ahmad

Unit 11: Sound - Important Questions And Answers 2024 By Sir Wasim Ahmad

Go To Index
Physics For Class X
Unit 11: Sound
Question & Answers

By Sir Wasim Ahmad

Unit 10: General Wave Properties - Physics II - For Class X (Science Group) - MCQs, Fill in the blanks and Concept Map

Go To Index
Unit 10: General Wave Properties
Physics II
For Class X (Science Group)

• MCQs From Text Book Exercise
• More MCQs
• Fill In The Blanks
• Concept Map

Multiple Choice Questions (MCQs)
From Text Book Exercise

Tick mark (✔) the correct answer:
1. A girl throws a small stone into a lake. Waves spread out from where the stone hits the water and travel to the bank of the lake. She notices that ten waves reach the side of the pond in a time of 5.0s. What is the frequency of the waves?
a) 0.50 Hz
b) 15 Hz
c) 2.0 Hz ✔
d) 50 Hz

2. Water waves can be used to show reflection, refraction, and diffraction. For each of these, which row shows whether or not the speed of the water waves changes?
Ans: (a)

-	Reflection	Refraction	Diffraction
a) ✔	Yes	Yes	Yes
b)	Yes	No	Yes
c)	No	Yes	No
d)	No	No	No

3. The diagrams show water waves that move more slowly after passing into shallow water. Which diagram shows what happens to the waves?
Ans: (c)

4. The diagram shows a water wave approaching a barrier with a gap.

The wave reaches point P. What is the name of the effect that causes he wave to reach point P?
a) Diffraction ✔
b) Dispersion
c) Reflection
d) Refraction

5. Water waves pass from deep into the shallow region and are then refracted. The characteristics of waves which will remain constant is:
a) direction
b) frequency ✔
c) speed
d) wavelength

6. Which is not a characteristic of a wave?
a) An amplitude
b) Period
c) Mass ✔
d) Velocity

7. When an oscillating object is in simple harmonic motion, its maximum speed occurs when the object is at its:
a) highest point
b) lowest point
c) equilibrium point ✔
d) extreme point

8. In an oscillating pendulum, the bob accelerates from its extreme position due to:
a) inertia
b) tension in the string
c) wind
d) gravitational force ✔

9. In the ball and bowl system, the mean position is at:
a) the earth
b) floor of the bowl
c) center of bowl ✔
d) extreme position

10. Oscillations are damped due to the presence of:
a) linear motion
b) restoring force
c) frictional force ✔
d) mechanical force

GO TO TOP

More Multiple Choice Questions (MCQs)
From Chapter

11. A wave transports this from one point to another point.
a) Matter
b) Energy ✔
c) Velocity
d) Amplitude

12. Waves that travel in a direction perpendicular to the direction of wave motion.
a) Sound waves
b) Longitudinal waves
c) Transverse waves ✔
d) None of them

13. Which one is NOT a transverse wave?
a) Water wave
b) Vibration in a guitar string
c) Electromagnetic wave
d) Sound wave ✔

14. It is the maximum displacement moved by a point on a vibrating body from the rest or mean position.
a) Amplitude ✔
b) Crest
c) Trough
d) Compression

15. SI unit of amplitude is:
a) second
b) meter / second
c) meter ✔
d) Hertz

16. It is a point on a surface wave where the displacement of the medium is at a maximum.
a) Amplitude
b) Crest ✔
c) Trough
d) Compression

17. Crest is:
a) negative / lower part of wave
b) negative / upper part of wave
c) positive / lower part of wave
d) positive / upper part of wave ✔

18. It is a point on a surface wave where the displacement of the medium is at a minimum:
a) Amplitude
b) Crest
c) Trough ✔
d) Compression

19. Waves that travel in a direction parallel to the direction of wave motion.
a) Electromagnetic waves
b) Longitudinal waves ✔
c) Transverse waves
d) None of them

20. Which one is an example of a longitudinal wave?
a) Water wave
b) Vibration in a guitar string
c) Electromagnetic wave
d) Sound wave ✔

21. This is a region where particles of a medium are closer together than average.
a) Rarefaction
b) Crest
c) Trough
d) Compression ✔

22. This is a region where the particles of a medium are further apart than average.
a) Rarefaction ✔
b) Crest
c) Trough
d) Compression

23. They do not need a medium for propagation.
a) Mechanical waves
b) Electromagnetic waves ✔
c) Sound waves
d) Water waves

24. Which one of them is an example of mechanical waves?
a) Sound waves
b) Water waves
c) Seismic waves
d) All of them ✔

25. Electromagnetic waves are comprised of:
a) transverse wave only ✔
b) longitudinal wave only
c) Both ‘a’ & ‘b’
d) None of them

26. Bouncing back of waves into the same medium by striking another medium surface is called:
a) reflection ✔
b) reflection
c) diffraction
d) None of them

27. Diffraction is only significant if the size of the gap is:
a) larger than the wavelength of the incident wave
b) smaller than the wavelength of the incident wave
c) about the same as the wavelength of the incident wave ✔
d) None of the above

28. The spreading of the waves near an obstacle is called:
a) reflection
b) refraction
c) diffraction ✔
d) None of them

29. What is the relation between frequency and time period of a wave?
a) f = T
b) f = ¹/_T ✔
c) f = 2T
d) f = ^T/₂

30. The SI unit of frequency is the:
a) second
b) meter
c) meter/sec
d) hertz ✔

31. The SI unit of wavelength is:
a) second
b) meter ✔
c) meter/sec
d) hertz

32. The speed of a wave can also be written as:
a) v = fƛ ✔
b) v = ^f/_ƛ
c) v = ^ƛ/_f
d) v = 2fƛ

33. Which expression represents the simple harmonic motion?
a) a ∝ 2x
b) a ∝ x
c) a ∝ -x ✔
d) a ∝ ¹/_x

34. Simple pendulum period is affected by: OR The period of a simple pendulum depends upon its:
a) length and gravity acceleration ✔
b) length and mass
c) mass and gravity acceleration
d) mass and amplitude

35. The period of a simple pendulum is independent of:
a) length and gravity acceleration
b) length and mass
c) mass and gravity acceleration
d) mass and amplitude ✔

36. The formula of time-period, T, for the simple pendulum executing SHM is:
a) 2π √g / l
b) 2π √l / g ✔
c) π √g / l
d) π √l /g

37. The waves that require a material medium for their propagation are called:
a) Matter waves
b) Electromagnetic waves
c) Mechanical waves ✔
d) All of them

38. The distance between any two consecutive crests or troughs is called:
a) frequency
b) time period
c) wavelength ✔
d) amplitude

39. The particles of the medium vibrate in longitudinal waves:
a) perpendicular to the direction of the wave motion
b) along the direction of wave motion ✔
c) opposite to the direction of the wave motion
d) do not vibrate at all

40. An example of mechanical waves is:
a) sound ✔
b) heat
c) light
d) All of them

41. A ripple tank is used to study the various forms of:
a) gases
b) solids
c) crystals
d) waves ✔

42. Which statement is TRUE for mechanical waves?
a) carry energy but do not need a medium
b) need medium but do not carry energy
c) carry energy and need a medium ✔
d) None of these

43. At the mean position of the pendulum, the potential energy of the pendulum is:
a) maximum
b) minimum ✔
c) zero
d) None of them

44. Shock absorbers in automobiles are one practical application of:
a) waves
b) SHM
c) damped motion ✔
d) None of these

45. The motion in which the friction reduces the mechanical energy of the system and the amplitude of motion reduces is called:
a) wave motion
b) SHM
c) vibratory motion
d) damped motion ✔

46. Time period is reciprocal of:
a) frequency ✔
b) amplitude
c) wavelength
d) pitch

47. The Water waves obey the laws of:
a) reflection & refraction
b) diffraction
c) Both ‘a’ & ‘b’ ✔
d) None of these

48. Which of the following device can produce both transverse and longitudinal waves?
a) A tuning fork
b) A slinky spring ✔
c) A ripple tank
d) A string

49. In Simple Harmonic Motion, the velocity at equilibrium position is:
a) maximum ✔
b) minimum
c) zero
d) constant

GO TO TOP

Fill In The Blanks

1. Up-and-down movements in the rope produce oscillations or vibrations.
2. A slinky is a pre-compressed helical or coiled spring.
3. A ripple tank is a glass tank of water used to demonstrate the basic properties of waves.
4. The particle movement is at right angles to the direction of the wave motion is a transverse wave.
5. A transverse wave is comprised of crest and trough.
6. The particle movement is in the same direction as the direction of wave motion, a longitudinal wave.
7. A longitudinal wave is comprised of compression and rarefaction.
8. The wave is a disturbance that transfers energy from one place to another.
9. Any substance that a wave can propagate through it is known as a medium.
10. Waves that transfer energy through matter are known as mechanical waves.
11. All mechanical waves travel through their media at different speeds depending upon the elasticity and inertial properties of the respective medium.
12. Waves that transfer energy, without the material medium are known as electromagnetic waves.
13. Ripple tank experiments demonstrate that water waves can be reflected, refracted, and diffracted.
14. When a wave enters from a region of deep water to a shallow, its wavelength and speed decrease.
15. The bending’of waves around obstacles or sharp edges is called the diffraction of waves.
16. When, an object oscillates about a fixed position its acceleration is directly Proportional to its displacement and is directed towards the mean position, its motion is called SHM.
17. A simple pendulum consists of a small metallic bob suspended from a light and in extensible string fixed at its upper end.
18. The period of a simple pendulum depends upon its length and acceleration due to gravity over that place.
19. An oscillating system in which friction has an effect is a damped system.
20. The amplitude of freely oscillating objects progressively decreases.

GO TO TOP

Concept Map

GO TO TOP