Electromagnetic waves

Telescopes are used to look at distant objects.

Some telescopes use lenses to form an image.

Figure 5 shows two parallel rays of light incident on a lens in a telescope.

The principal focus of the lens is labelled F.

What type of lens is shown in Figure 5 ?

Complete the ray diagram in Figure 5.

The James Webb Space Telescope can detect electromagnetic radiation beyond the visible spectrum.

The shortest wavelength of electromagnetic radiation that can be detected by the James Webb Space Telescope is 0.60 m.

speed of electromagnetic radiation = 3.0 × 10⁸ m/s

Calculate the frequency of electromagnetic radiation that has a wavelength of

Use the Physics Equations Sheet.

Complete the sentence.

Electromagnetic radiation detected from distant galaxies is red-shifted.

This means that the electromagnetic radiation shows an increase in

Why is the electromagnetic radiation from distant galaxies red-shifted?

Tick () one box.

The James Webb Space Telescope has detected electromagnetic radiation from many different galaxies.

Electromagnetic radiation from one of the galaxies detected shows the greatest red-shift ever observed.

What conclusion can be made about the distance to this galaxy?

The James Webb Space Telescope is an artificial satellite that orbits the Sun at a constant speed.

Explain why the velocity of the satellite changes as it orbits the Sun.

A group of stars is called a galaxy.

What is the name of our galaxy?

Tick (✓) one box.

The Sun is one of the stars in our galaxy.

What was the Sun originally formed from?

Tick (✓) one box.

Which of the following forces was involved in the formation of the Sun?

Tick (✓) one box.

Stars produce light because they release energy.

Complete the sentence.

Choose the answer from the box.

Visible light and infrared radiation travel from the Sun to the Earth.

Which statement describes the time taken for visible light and infrared radiation to travel from the Sun to the Earth?

Tick (✓) one box.

Infrared radiation has a longer wavelength than visible light.

Complete the sentence.

Choose the answer from the box.

Compared with the frequency of infrared radiation, the frequency of

The Sun and the Earth both emit infrared radiation.

How does the rate of infrared radiation emitted by the Sun compare with the rate of infrared radiation emitted by the Earth?

Give a reason for your answer.

Tick (✓) one box.

Figure 7 represents a transverse wave.

Which arrow represents the amplitude of the wave?

Tick (✓) one box.

Which arrow represents the wavelength of the wave?

Tick (✓) one box.

A wave has a frequency of 5000 Hz.

Calculate the period of the wave.

Use the equation:

Give one example of a transverse wave that can travel through a vacuum.

Figure 8 represents a longitudinal wave.

Which point is at the centre of a rarefaction?

Tick (✓) one box.

A sound wave has a frequency of 750 Hz.

speed of sound in air = 330 m/s

Calculate the wavelength of the sound wave.

Use the equation:

Describe a method that could be used to determine the speed of sound in air.

When a sound wave moves from air into water, the speed of the wave increases.

The frequency of the sound wave does not change.

Complete the sentence.

Choose the answer from the box.

When a sound wave moves from air into water its

A student investigated the refraction of light by a glass block.

Figure 13 shows the protractor used to measure the angles of incidence and the angles of refraction.

What is the resolution of the protractor used to measure the angles?

Table 1 shows the results.

Describe a method the student could have used to obtain the data in Table 1.

You may include a labelled diagram.

Figure 14 shows some of the results.

The student measured the angles of refraction for two additional angles of incidence.

Table 2 shows the additional results.

Complete Figure 14.

You should:

• plot the results from Table 2

• draw the line of best fit.

How does Figure 14 show that the angle of refraction is not directly proportional to the angle of incidence?

Figure 15 shows a diagram of a car headlight.

The headlight has a lamp, a reflective surface and a transparent cover.

Figure 16 shows a ray of light incident on the reflective surface.

Complete Figure 16 to show the reflected ray of light.

You should include the normal line at the point where the incident ray meets the reflecting surface.

Rays of light pass through the transparent cover of the headlight.

Which diagram shows how a ray of light passes through the transparent cover?

Tick (✓) one box.

A student investigated the refraction of light by a glass block.

Figure 1 shows the protractor used to measure the angles of incidence and the angles of refraction.

What is the resolution of the protractor used to measure the angles?

Table 1 shows the results.

Describe a method the student could have used to obtain the data in Table 1.

You may include a labelled diagram.

Figure 2 shows some of the results.

The student measured the angles of refraction for two additional angles of incidence.

Table 2 shows the additional results.

Complete Figure 2.

You should:

• plot the results from Table 2

• draw the line of best fit.

How does Figure 2 show that the angle of refraction is not directly proportional to the angle of incidence?

Figure 3 shows a diagram of a car headlight.

The headlight has a lamp, a reflective surface and a transparent cover.

Figure 4 shows a ray of light incident on the reflective surface.

Complete Figure 4 to show the reflected ray of light.

You should include the normal line at the point where the incident ray meets the reflecting surface.

Rays of light pass through the transparent cover of the headlight.

Which diagram shows how a ray of light passes through the transparent cover?

Tick () one box.

Radio waves and gamma rays both transfer energy.

Give three other similarities between radio waves and gamma rays.

Both radio waves and gamma rays are used in medicine.

Give one medical use of gamma rays.

Explain why exposure to gamma rays can be harmful but exposure to radio waves is not harmful.

Some medical scanners produce radio waves at a specific frequency.

Explain how radio waves are produced at a specific frequency.

A student investigated the refraction of light through a glass block. Figure 14 shows the ray box used. The student aimed the beam of light from the ray box towards a glass block. The student measured the angle of incidence at the point where the light entered the glass block.

Why is using a wide beam of light less likely to give accurate results than using a narrow beam? Tick (✓) one box.

Figure 15 shows the beam of light incident on the glass block.

Complete Figure 15 to show the path taken by the beam of light through the glass block and back into the air.

Figure 16 shows the protractor used by the student.

What is the resolution of the protractor? Tick (✓) one box.

For one angle of incidence the student measured the angle of refraction three times. The three measurements were: 35° 31° 33° Calculate the mean angle of refraction.

The student placed a red filter in front of the white beam of light. Only red light passes through the filter.

Complete the sentence.

When white light is incident on the red filter, all colours except for red are

Use the Physics Equations Sheet to answer questions 06.6 and 06.7.

Light has a wave speed of 3.0 × 10⁸ m/s in air. The frequency of the red light is 4.0 × 10¹⁴ Hz. Calculate the wavelength of the red light in air.

A student investigated the behaviour of light. The student used a mirror with a smooth surface to investigate reflection. Figure 17 shows the equipment used.

What name is given to reflection from a smooth surface?

The student measured the angle of reflection for different angles of incidence. Table 2 shows the results.

What conclusion can be made from the results in Table 2 ?

What type of error caused the variation in the results for the angle of reflection? Suggest one cause of this error.

The student also investigated the refraction of light.

Figure 18 shows the path of a ray of light through a glass block.

Why has refraction not occurred?

The student measured the angle of refraction for different angles of incidence. Figure 19 shows the protractor used.

When the angle of incidence was 10° the student measured the angle of refraction four times. The student recorded the measurements as: 6.0° 6.3° 6.4° 5.8° Explain why the student should not have recorded these results when using the protractor in Figure 19 to make the measurements.

Figure 20 shows what happens to wave fronts as they pass across the boundary between air and glass.

Explain in terms of the wave fronts, why refraction happens at the boundary between air and glass.

Ultraviolet and visible light are both parts of the electromagnetic spectrum.

How does the speed of ultraviolet in a vacuum compare to the speed of visible light in a vacuum?

Tick (✓) one box.

Figure 9 shows parts of the electromagnetic spectrum.

Which letters represent the positions of ultraviolet and visible light in the electromagnetic spectrum?

Table 3 shows the range of wavelengths for different types of ultraviolet.

Determine which type of ultraviolet shown in Table 3 has the largest range of wavelengths.

To gain full marks you must calculate the range of wavelengths for each type of ultraviolet.

Figure 10 shows how different types of ultraviolet are absorbed by the ozone layer in the Earth’s atmosphere.

Table 4 shows the relative ionising power from each type of ultraviolet.

Explain the importance of the ozone layer in reducing the risk to people from all types of ultraviolet.

Use Figure 10 and Table 4.

The Sun emits visible light.

A student concludes that visible light is not absorbed by the ozone layer.

Give one piece of evidence that shows the student’s conclusion is correct.

Figure 11 shows white light incident on a colour filter.

Complete the sentence.

Choose the answers from the box.

A student used a ray box to shine a ray of light through air into a glass block.

The student investigated how the angle of refraction varied with the angle of incidence.

Table 5 shows the results.

Describe a method the student could have used to obtain the results in Table 5.

Your answer may include a labelled diagram.

Complete Figure 16 using data from Table 5.

• Label the axes.

• Plot the remaining data.

• Draw a line of best fit.

You should:

• draw the normal line

• draw the reflected ray.

Two students investigated the reflection of light by a plane mirror.

Figure 18 shows the different equipment the students used.

Explain two ways that Method A is better than Method B.

A student used a ray box to shine a ray of light through air into a glass block.

The student investigated how the angle of refraction varied with the angle of incidence.

Table 1 shows the results.

Describe a method the student could have used to obtain the results in Table 1.

Your answer may include a labelled diagram.

Figure 2 is an incomplete graph of the results.

Complete Figure 2 using data from Table 1.

Label the axes.

Plot the remaining data.

Draw a line of best fit.

Complete the ray diagram in Figure 3 to show the reflection of light from the surface of a plane mirror.

You should:

draw the normal line

draw the reflected ray.

Two students investigated the reflection of light by a plane mirror.

Figure 4 shows the different equipment the students used.

Explain two ways that Method A is better than Method B.

There are different groups of waves in the electromagnetic spectrum.

Figure 8 shows the position of three groups of the waves.

Which letter shows the position of infrared? Tick (✓) one box.

A student investigated how the colour of a surface affects the amount of infrared the

surface absorbs. Figure 9 shows the equipment used.

Complete the sentence. Choose the answer from the box.

a control the dependent the independent

In this investigation the distance between each flask and the infrared heater

The student wrote the hypothesis: ‘Surface colour of the flask affects the amount of infrared absorbed when the heater is switched on for five minutes.’ Describe how the equipment in Figure 9 could be used to test this hypothesis.

Table 1 shows the results.

Which one of the results for the black flask is anomalous?

The anomalous result was caused by reading the thermometer incorrectly. What should the student do with the anomalous result?

Calculate the mean temperature increase for the silver flask.

Mean temperature increase = °C

What conclusion can be made from Table 1? Tick (✓) one box.

Ultraviolet is a type of electromagnetic wave.

Give one use of ultraviolet.

An ultraviolet wave has a wavelength of 300 nanometres. Which of the following is equal to 300 nanometres? Tick (✓) one box.

The speed of ultraviolet waves is 3 × 10⁸ m/s. Calculate the frequency of the ultraviolet wave. Use your answer to Question 05.2

Table 1 gives the wavelength of an ultraviolet wave and three other electromagnetic waves.

Draw one line from each wave to the name of the wave.

Electromagnetic waves are transverse. Some other types of wave are longitudinal.

Describe the difference between transverse and longitudinal waves.

Figure 10 shows the position of three types of wave in the electromagnetic spectrum.

Which letter represents the position of X-rays in the electromagnetic spectrum? Tick (✓) one box.

A doctor needs to obtain an image of a bone in a patient’s injured arm. The doctor takes an X-ray of the arm.

Give one possible harmful consequence of receiving a dose of X-ray radiation.

Table 3 gives information about two methods of bone imaging.

Compare the risk of harm to the patient of having an X-ray rather than a CT scan.

Which of the following is the same as 6.0 millisieverts? Tick (✓) one box.

The patient received a total radiation dose of 2.5 millisieverts during one year. Calculate the percentage of this dose that came from one X-ray of the arm. Use the data in Table 3.

A student investigated the refraction of light at the boundary between air and glass. Figure 3 shows the ray box used.

The ray of light from the ray box should be as narrow as possible. Explain why using a wider ray would give less accurate results than using a narrower ray.

Figure 4 shows the results.

Estimate the angle of refraction when the angle of incidence is 80°. Show on Figure 4 how you obtained your answer.

Describe a method the student could have used to obtain the results shown in Figure 4.

The student repeated each measurement three times. When the angle of incidence was 40° the three measured values for the angle of refraction were 28° 25° 22° Estimate the uncertainty in the angle of refraction when the angle of incidence was 40°. Show how you determine your estimate.

What property of the light wave changes when it is refracted?

Tick (✓) one box.

Figure 8 shows a student playing with a remote-controlled car.

The remote control transmits radio waves to the car aerial. The transmitted radio waves have a frequency of 320 MHz. speed of radio waves = 3.0 10⁸ m/s Calculate the wavelength of the radio waves. Give the unit.

The car aerial is connected to an electrical circuit in the car. Describe what happens in the electrical circuit when the car aerial absorbs radio waves.

The car produces sound waves. Give two ways in which radio waves are different to sound waves.

Figure 9 shows the distance-time graph for the first 30 seconds of the car’s motion.

Describe the motion of the car during the first 30 seconds.

Determine the speed of the car 20 seconds after it started to move.

A different car accelerated from 0.12 m/s to 0.52 m/s. The acceleration of the car was 0.040 m/s². The work done to accelerate the car was 0.48 J. Calculate the resultant force needed to accelerate the car.

Explain why the car has a maximum speed.

Figure 11 shows the position of three types of wave in the electromagnetic spectrum.

Which letter represents infrared in the electromagnetic spectrum?

Tick (✓) one box.

What is infrared used for? Tick (✓) one box.

An infrared camera produces a colour image. Different colours show different temperatures. People emit infrared radiation. Figure 12 shows how the colour of the image of a person on an infrared camera depends on the person’s body temperature.

Complete the sentence. Choose the answer from the box.

The image produced by an infrared camera of a person with a body temperature of

Rescue workers use infrared cameras to search for people trapped under rubble after an earthquake. How does the image of a trapped person change if the person’s body temperature drops from 37 °C to 33 °C?

A student investigated how the type of surface affects the amount of infrared the surface radiates. Figure 13 shows the equipment used.

Complete the sentence. Choose the answer from the box.

Describe how the equipment shown in Figure 13 would be used to compare the infrared radiation emitted from the vertical surfaces of the cube.

Table 1 shows the results.

What is the resolution of the infrared detector? Tick (✓) one box.

The bar chart in Figure 14 shows two of the results.

Complete the bar chart to show all of the results.

Give one conclusion that can be made from the results.

A student used a ray box and glass block to investigate refraction of light. Figure 15 shows a ray of light entering the glass block.

Figure 15

In Figure 15, the angle of incidence is labelled with the letter i. Label the angle of refraction in Figure 15 with the letter r.

Measure the angle of incidence in Figure 15.

Complete Figure 15 to show the path taken by the ray of light through the glass block and out into the air.

Complete the sentence. Choose an answer from the box.

The student repeated the measurement three times and calculated the mean to

Table 2 shows the student’s values for the angles of incidence and the mean angles of refraction.

For an angle of incidence of 40° the three measurements for the angle of refraction were: 23° 27° 25° Calculate the value of X in Table 2.

Complete the sentence. Choose the answer from the box.

The student used the data in Table 2 and correctly concluded that the angle of refraction is the angle of incidence used.

Why is the student’s conclusion only valid for angles of incidence between 20° and 50°?

The student repeated the investigation using a transparent plastic block. Why did the student use a transparent block and not an opaque block?

The student wanted to compare the refraction caused by the plastic with the refraction caused by the glass. What must the student keep the same for both the plastic block and the glass block?

Tick (✓) one box.

Figure 12 shows the electromagnetic spectrum.

Which statement is correct for the direction of the arrow in Figure 12 ? Tick (✓) one box.

Explain how the properties of X-rays make them suitable for the medical imaging of bones.

A student investigated the infrared radiation emitted from the sides of a hollow metal cube. The sides of the cube are different colours or textures. Figure 13 shows the equipment used.

Boiling water was poured into the cube. The amount of infrared radiation emitted from each vertical surface was then measured.

Boiling water is a hazard in this investigation. Suggest how the risk of harm could be reduced in this investigation.

What is the control variable in this investigation?

Table 2 shows the results.

The four temperature values in Table 2 cannot be used to show that the infrared detector gives precise readings. Give the reason why.

The student looked at the data in Table 2 and concluded: ‘A black surface always emits more infrared radiation than a white surface.’ Explain how using an infrared detector with a resolution of 1 °C would have affected the student’s conclusion.

Albedo is a measure of the amount of solar radiation reflected by an object compared to the total solar radiation incident on the object. A perfect reflector has an Albedo value of 1.0 A perfect absorber has an Albedo value of 0.0

What is the Albedo value of a perfect black body?

Figure 14 shows two points, A and B, just above the Earth’s surface.

The average Albedo value of the Earth’s surface is 0.3 The Albedo value of thick cloud varies between 0.6 and 0.9 At night the air at point A cools faster than the air at point B. Explain why.

Figure 10 shows the position of three types of wave in the electromagnetic spectrum.

Figure 10

Which position shows where visible light is in the spectrum? Tick one box.

Which one of the statements about electromagnetic waves is correct? Tick one box.

Give one possible danger of exposing your skin to ultraviolet radiation.

Having an X-ray taken exposes a person to ionising radiation. Table 3 gives the average radiation dose for an X-ray of the chest and an X-ray of the upper digestive system.

The risk of an X-ray causing cancer is about 1 in 20 000 for each mSv of radiation received. Compare the risk of developing cancer from having an X-ray of the upper digestive system with the risk from having an X-ray of the chest. Use the data in Table 3.

Light is usually described as a wave. Light can also be described as a stream of particles. These are two different scientific models of light.

Which statement describes a scientific model? Tick one box.

Why do scientists sometimes have different models like the wave and particle models of light?

Sometimes an old scientific model is replaced by a new model. Explain why scientists replace an old scientific model with a new model. Include an example from Physics in your answer.

Some students used water waves in a ripple tank to model the behaviour of light waves.

Figure 16 shows what happens to the wave fronts as they pass the boundary between deep water and shallower water.

Figure 16

Explain why refraction happens at the boundary between the deep water and shallower water.

Figure 17 shows the wave fronts travelling parallel to the boundary between deep water and shallower water.

Figure 17

Explain why the wave fronts in Figure 17 do not refract at the boundary.