Waves
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Transverse and Longitudinal Waves
SubtopicTransverse and Longitudinal Waves under Waves for Grade 9 IB.
Preview questions (no answers)
- 1.
How is wave speed calculated?
A.B.C.D. - 2.
Which electromagnetic radiation is used to cook food in a kitchen appliance?
A.X-rays
B.Microwaves
C.Radio waves
D.Gamma rays
- 3.
What is the name for the high-pressure regions in a longitudinal wave?
A.Rarefactions
B.Crests
C.Troughs
D.Compressions
- 4.
What is the speed of a wave with a frequency of and a wavelength of ?
A.B.C.D. - 5.
What happens to the wavelength of light as it moves from air () into water ()?
A.It increases
B.It decreases
C.It remains the same
D.It doubles
- 6.
Which of these quantities is measured in Hertz ()?
A.Wavelength
B.Frequency
C.Wave speed
D.Amplitude
- 7.
Which type of electromagnetic radiation is primarily responsible for the heating effect of the Sun on Earth?
A.Ultraviolet
B.Infrared
C.X-rays
D.Radio waves
- 8.
What is the phase difference between a compression and the next rarefaction in a longitudinal sound wave?
A.B.C.D. - 9.
Which of the following is NOT a property of all electromagnetic waves in a vacuum?
A.They are transverse waves
B.They travel at
C.They have the same frequency
D.They can be polarized
- 10.
The critical angle for a certain medium-air interface is . What is the speed of light in this medium?
A.B.C.D.
Download the worksheet for Waves - Transverse and Longitudinal Waves to practice offline. It includes additional chapter-level practice questions.
The Electromagnetic Spectrum
SubtopicThe Electromagnetic Spectrum under Waves for Grade 9 IB.
Preview questions (no answers)
- 1.
What is the relationship between the wavelength and the frequency of an electromagnetic wave?
A.They are directly proportional.
B.They are inversely proportional.
C.They are equal to each other.
D.They have no relationship.
- 2.
Optical fibers primarily use which parts of the electromagnetic spectrum to transmit data?
A.X-rays and Gamma rays
B.Radio waves and Microwaves
C.Visible light and Infrared
D.Ultraviolet and X-rays
- 3.
Which of the following is true regarding the danger of electromagnetic waves?
A.Radio waves are the most dangerous because they are the longest.
B.Visible light is the only dangerous part of the spectrum.
C.High-frequency waves like Gamma rays are generally more dangerous to biological tissue.
D.Low-frequency waves carry more energy and cause more damage.
- 4.
Which color of visible light has the highest energy per photon?
A.Red
B.Yellow
C.Green
D.Violet
- 5.
Which property of X-rays makes them suitable for use in computerized tomography (CT scans)?
A.They have a very long wavelength.
B.They can be reflected by soft tissues.
C.They are absorbed to different extents by different body tissues.
D.They have the lowest energy in the electromagnetic spectrum.
- 6.
Which of these represents the correct order of the visible light spectrum from longest wavelength to shortest wavelength?
A.Violet, Indigo, Blue, Green, Yellow, Orange, Red
B.Red, Orange, Yellow, Green, Blue, Indigo, Violet
C.Green, Blue, Red, Violet, Yellow, Orange, Indigo
D.Violet, Red, Orange, Yellow, Green, Blue, Indigo
- 7.
Calculate the frequency of an electromagnetic wave that has a wavelength of meters.
A.Hz
B.Hz
C.Hz
D.Hz
- 8.
A pulsar emits a beam of electromagnetic radiation that sweeps across Earth every 0.033 seconds. If the radiation detected is in the X-ray part of the spectrum, what can we conclude about the 'source' of these waves compared to a pulsar emitting radio waves?
A.The X-ray pulsar is much colder than the radio pulsar.
B.The X-ray pulsar involves higher-energy processes, likely involving much stronger magnetic fields or higher temperatures.
C.The X-ray pulsar is much further away, and the waves have gained energy during travel.
D.The radio pulsar waves have a higher frequency but lower energy per photon.
- 9.
What is the primary physical reason that 'Blue' light scatters more in the Earth's atmosphere than 'Red' light, giving the sky its color?
A.Blue light travels slower in the atmosphere than red light.
B.The shorter wavelength of blue light is closer to the size of the gas molecules, leading to more efficient Rayleigh scattering.
C.Red light is absorbed by the ozone layer, leaving only blue light to be seen.
D.The atmosphere acts as a giant prism that refracts blue light at a steeper angle toward the surface.
- 10.
Which of the following properties of X-rays makes them suitable for 'X-ray Crystallography' (studying the arrangement of atoms in a crystal)?
A.X-rays have a wavelength comparable to the distance between atoms in a crystal, allowing for diffraction patterns to form.
B.X-rays are absorbed by the electrons, causing the atoms to glow in visible light.
C.X-rays have a low frequency, which prevents them from moving the atoms while they are being measured.
D.X-rays are the only EM waves that can travel through solid solids without slowing down.
Download the worksheet for Waves - The Electromagnetic Spectrum to practice offline. It includes additional chapter-level practice questions.
Reflection and Refraction
SubtopicReflection and Refraction under Waves for Grade 9 IB.
Preview questions (no answers)
- 1.
A pool of water appears shallower than it actually is. This is due to:
A.Reflection
B.Refraction
C.Diffraction
D.Absorption
- 2.
What is the name of the ray that strikes a surface?
A.Reflected ray
B.Normal ray
C.Incident ray
D.Emergent ray
- 3.
Which of the following describes 'total internal reflection'?
A.Light bending as it enters glass
B.Light reflecting off a mirror
C.Light reflecting back into a denser medium at the boundary
D.Light spreading out into a rainbow
- 4.
If the angle between the incident ray and the reflected ray is , what is the angle of incidence?
A.B.C.D. - 5.
A ray of light passes through three parallel layers of different transparent materials: Medium 1, Medium 2, and Medium 3. The behavior of the ray at each boundary is described in the flowchart. Based on these observations, which of the following correctly ranks the refractive indices () of the three media from highest to lowest?
A.B.C.D. - 6.
Which of the following is true about the absolute refractive index of any material?
A.It is always less than .
B.It is always equal to .
C.It is always greater than or equal to .
D.It has units of meters per second.
- 7.
A ray of light moves from glass () to water (). Calculate the critical angle for this interface.
A.B.C.D. - 8.
The refractive index of a certain glass is . If light of wavelength in air enters this glass, what is the wavelength of the light in the glass?
A.B.C.D. - 9.
Light passes from a medium with to a medium with . If the angle of incidence is , what is the angle of refraction?
A.B.C.D. - 10.
For a ray of light entering a medium from a vacuum, if the angle of incidence is and the angle of refraction is , what is the value of the refractive index?
A.B.C.D.
Download the worksheet for Waves - Reflection and Refraction to practice offline. It includes additional chapter-level practice questions.
Preview questions (no answers)
- 1.
In a sound wave, what is a rarefaction?
A.A point of maximum pressure
B.A point of minimum pressure
C.The start of the wave
D.The end of the wave
- 2.
What does it mean if a sound is 'ultrasonic'?
A.It is very loud
B.It is very fast
C.It has a frequency too high for humans to hear
D.It has a frequency too low for humans to hear
- 3.
Which sound wave property is directly related to the energy it carries?
A.Pitch
B.Amplitude
C.Wavelength
D.Speed
- 4.
What is the threshold of human hearing in decibels?
A.B.C.D. - 5.
Which part of the human ear is responsible for converting sound vibrations into electrical signals for the brain?
A.The eardrum
B.The ossicles
C.The cochlea
D.The auditory canal
- 6.
A wave on an oscilloscope has a frequency of . What is the time required for one full wave to be drawn on the screen?
A.B.C.D. - 7.
Which of the following changes would increase the speed of a sound wave in a specific sample of air?
A.Increasing the frequency of the sound
B.Increasing the amplitude of the sound
C.Increasing the temperature of the air
D.Decreasing the wavelength of the sound
- 8.
A sound wave travels through air at . If the pressure variations at a point change from maximum to minimum in , what is the wavelength of the sound?
A.B.C.D. - 9.
A person claps their hands at a rate of claps per second. They are at a distance from a wall and the echoes coincide with the next clap. If the speed of sound is , what is the distance ?
A.B.C.D. - 10.
Two waves with the same frequency and amplitude travel in opposite directions in a medium and interfere. What is the distance between a node and the nearest antinode?
A.B.C.D.
Download the worksheet for Waves - Properties of Sound to practice offline. It includes additional chapter-level practice questions.
Preview questions (no answers)
- 1.
In a vacuum, all electromagnetic waves have the same:
A.Frequency
B.Wavelength
C.Speed
D.Amplitude
- 2.
Calculate speed if wavelength is m and period is seconds.
A.1 m/s
B.0.25 m/s
C.4 m/s
D.2.5 m/s
- 3.
A wave with a frequency of Hz has a period of:
A.2 s
B.0.5 s
C.1 s
D.4 s
- 4.
Which equation relates wavelength, speed, and period?
A.B.C.D. - 5.
A wave source produces 1200 waves every minute. If the speed of the waves is , what is the wavelength?
A.0.5 m
B.0.008 m
C.2 m
D.20 m
- 6.
The wavelength of a green light is . What is the period of the wave? ()
A.1.83 x 10^-15 s
B.C.D.1.83 x 10^-7 s
- 7.
A wave has a frequency of and a speed of . What is the distance between a crest and its neighboring trough?
A.0.2 m
B.0.1 m
C.5 m
D.0.05 m
- 8.
Calculate the frequency of a violet light wave which has a wavelength of in a vacuum ().
A.B.C.D. - 9.
A tuning fork vibrates at . If the speed of sound is , what is the distance between two points that are degrees out of phase?
A.B.C.D. - 10.
An earthquake wave has a wavelength of and a frequency of . How long does it take for the wave to reach a city away?
A.B.C.D.
Download the worksheet for Waves - Wave Equation to practice offline. It includes additional chapter-level practice questions.
Preview questions (no answers)
- 1.
If you look through a glass prism at a white object, you often see colored edges. This is caused by:
A.Refraction
B.Reflection
C.Dispersion
D.Diffraction
- 2.
In the context of light, what does the term 'Refraction' mean?
A.Bouncing of light
B.Bending of light as it enters a new medium
C.Light traveling in a straight line
D.The absorption of light
- 3.
Which color has the largest wavelength in the visible spectrum?
A.Violet
B.Indigo
C.Blue
D.Red
- 4.
The word 'Polychromatic' refers to light that has:
A.Only one color
B.Many colors
C.No color
D.Invisible color
- 5.
Which of the following colors of light has the largest wavelength?
A.Indigo
B.Green
C.Orange
D.Blue
- 6.
A student sees a spectrum of light on a wall. Which phenomenon caused the white light to separate into these colors?
A.Diffraction
B.Dispersion
C.Total Internal Reflection
D.Scattering
- 7.
Which of the following light waves would be refracted the least when entering glass at an angle?
A.Light with frequency Hz
B.Light with frequency Hz
C.Light with frequency Hz
D.Light with frequency Hz
- 8.
A ray of light goes from crown glass to flint glass. Flint glass has a higher dispersive power and a higher refractive index than crown glass. What happens to the dispersion of the light beam?
A.The beam will become more dispersed (the spectrum will widen).
B.The beam will become less dispersed (the spectrum will narrow).
C.The colors will recombine into white light.
D.The light will stop being dispersed and only refract.
- 9.
Which of the following describes the 'mean' refractive index in most optical calculations involving the visible spectrum?
A.The refractive index for yellow light (-line of Sodium).
B.The average of the refractive indices of violet and red light.
C.The refractive index of green light at nm.
D.The refractive index of white light itself.
- 10.
If you are designing a high-quality camera lens, how would you minimize chromatic aberration using dispersion principles?
A.Combine a positive lens of one glass type with a negative lens of a different glass type.
B.Use only one type of glass but make the lens very thick.
C.Coat the lens with a material that has the same refractive index for all colors.
D.Make the lens perfectly flat on both sides.
Download the worksheet for Waves - Dispersion to practice offline. It includes additional chapter-level practice questions.
Imaging and Applications of Waves
SubtopicImaging and Applications of Waves under Waves for Grade 9 IB.
Preview questions (no answers)
- 1.
Why does a red apple appear red under white light?
A.It absorbs red light
B.It reflects red light and absorbs other colors
C.It transmits red light
D.It creates its own red light
- 2.
What is the purpose of the optic nerve in the human eye?
A.To focus light
B.To control light entry
C.To carry signals to the brain
D.To protect the eye
- 3.
Which of the following materials is opaque?
A.Clear glass
B.Air
C.A wooden door
D.Pure water
- 4.
What happens to the wavelength of a wave if the frequency increases while the speed stays constant?
A.Wavelength increases
B.Wavelength decreases
C.Wavelength stays the same
D.Wavelength becomes infinite
- 5.
A light ray enters a semi-circular glass block at the center of the flat face. If the angle of incidence is , the ray will:
A.Reflect back along the same path.
B.Pass straight through without bending.
C.Bend away from the normal.
D.Undergo total internal reflection.
- 6.
Which of the following is a disadvantage of using X-rays for medical imaging?
A.They cannot penetrate soft tissues.
B.They are ionizing radiation and can damage living cells.
C.They are too expensive for common use.
D.The images produced are low resolution.
- 7.
An endoscope used by doctors to see inside the body works based on which principle?
A.Diffraction through narrow tubes.
B.Total internal reflection in optical fibers.
C.Refraction through a series of lenses.
D.X-ray transmission.
- 8.
A lens of focal length is placed in contact with a lens of focal length . What is the combined power of this lens system?
A.B.C.D. - 9.
Calculate the frequency of a microwave with a wavelength of 3 cm in a vacuum. ()
A.B.C.D. - 10.
Which of the following statements about P-waves in seismology is correct?
A.They are longitudinal waves and can travel through both solids and liquids.
B.They are transverse waves and can only travel through the Earth's crust.
C.They are slower than S-waves and are the second to arrive at a station.
D.They are surface waves that cause the most damage during an earthquake.
Download the worksheet for Waves - Imaging and Applications of Waves to practice offline. It includes additional chapter-level practice questions.
Preview questions (no answers)
- 1.
As waves diffract through a gap, what happens to their direction of travel?
A.They all continue straight
B.They spread out over a range of angles
C.They reverse direction
D.They turn exactly 90 degrees
- 2.
Which of the following waves has the longest wavelength and thus diffracts the most around buildings?
A.Gamma rays
B.X-rays
C.Visible light
D.Radio waves
- 3.
The pattern of wave fronts becoming circular after a gap is a visual indicator of:
A.Reflection
B.Diffraction
C.Refraction
D.Absorption
- 4.
Which would diffract more through a classroom door?
A.A high-pitched whistle (short wavelength)
B.A low-pitched drum beat (long wavelength)
C.They diffract the same
D.Visible light from a torch
- 5.
Which of the following statements is true about diffraction through two slits?
A.It only involves reflection.
B.It leads to interference between the two diffracted waves.
C.It produces a single straight line on a screen.
D.It is called refraction.
- 6.
In a ripple tank, how can you make the wavelength larger to increase diffraction?
A.Increase the frequency of the motor.
B.Decrease the frequency of the motor.
C.Add more water to increase depth.
D.Decrease the amplitude of the motor.
- 7.
Diffraction proves that light has:
A.Particle properties.
B.Wave properties.
C.Magnetic properties.
D.No mass.
- 8.
As the wavelength of a wave becomes much larger than the size of an obstacle, what happens to the shadow cast by that obstacle?
A.The shadow becomes sharper and more defined.
B.The shadow disappears as the wave diffracts completely around the obstacle.
C.The shadow becomes larger than the obstacle itself.
D.The shadow turns into a bright spot due to reflection.
- 9.
Why does diffraction provide evidence that light is a wave and not a beam of particles (corpuscles)?
A.Particles would spread out more than waves when passing through a gap.
B.Particles would move in straight lines and leave a sharp-edged shadow, unlike the observed spreading of light.
C.Waves cannot travel through a vacuum, but light can.
D.Waves always travel at the same speed, whereas particles can speed up.
- 10.
Which of the following changes would increase the amount of diffraction seen in a ripple tank?
A.Using waves with a higher frequency.
B.Using a wider gap in the barrier.
C.Using waves with a larger amplitude.
D.Using waves with a lower frequency.
Download the worksheet for Waves - Diffraction to practice offline. It includes additional chapter-level practice questions.