Option C: Imaging

Explain the cause of the radio-frequency emissions from a patient’s body during nuclear magnetic resonance (NMR) imaging.

Explain the cause of the radio-frequency emissions from a patient’s body during nuclear magnetic resonance (NMR) imaging.

Explain the cause of the radio-frequency emissions from a patient’s body during nuclear magnetic resonance (NMR) imaging.

Outline how a gradient field allows NMR to be used in medical resonance imaging.

Outline how a gradient field allows NMR to be used in medical resonance imaging.

Outline how a gradient field allows NMR to be used in medical resonance imaging.

Calculate the maximum angle β for light to travel through the fibre.

Refractive index of core       = 1.50
Refractive index of cladding = 1.48

Calculate the maximum angle β for light to travel through the fibre.

Refractive index of core       = 1.50
Refractive index of cladding = 1.48

Calculate the maximum angle β for light to travel through the fibre.

Refractive index of core       = 1.50
Refractive index of cladding = 1.48

A technician operates an X-ray machine that takes 100 images each day. Estimate the width of the lead screen that is required so that the total exposure of the technician in 250 working days is equal to the exposure that the technician would receive from one X-ray exposure without the lead screen.

A technician operates an X-ray machine that takes 100 images each day. Estimate the width of the lead screen that is required so that the total exposure of the technician in 250 working days is equal to the exposure that the technician would receive from one X-ray exposure without the lead screen.

A technician operates an X-ray machine that takes 100 images each day. Estimate the width of the lead screen that is required so that the total exposure of the technician in 250 working days is equal to the exposure that the technician would receive from one X-ray exposure without the lead screen.

Determine the position of the image.

Determine the position of the image.

Determine the position of the image.

Explain, with appropriate calculations, why a gel is used between the transducer and the skin.

Explain, with appropriate calculations, why a gel is used between the transducer and the skin.

Explain, with appropriate calculations, why a gel is used between the transducer and the skin.

Outline how ultrasound is generated for medical imaging.

Outline how ultrasound is generated for medical imaging.

Outline how ultrasound is generated for medical imaging.

Describe one advantage and one disadvantage of using high frequencies ultrasound over low frequencies ultra sound for medical imaging.

Describe one advantage and one disadvantage of using high frequencies ultrasound over low frequencies ultra sound for medical imaging.

Describe one advantage and one disadvantage of using high frequencies ultrasound over low frequencies ultra sound for medical imaging.

Calculate the density of skin.

Calculate the density of skin.

Calculate the density of skin.

Suggest one reason why doctors use ultrasound rather than X-rays to monitor the development of a fetus. 

Suggest one reason why doctors use ultrasound rather than X-rays to monitor the development of a fetus. 

Suggest one reason why doctors use ultrasound rather than X-rays to monitor the development of a fetus. 

Calculate the maximum attenuation allowed for the signal.

Calculate the maximum attenuation allowed for the signal.

Calculate the maximum attenuation allowed for the signal.

It is proposed to build an array of radio telescopes such that the maximum distance between them is 3800 km. The array will operate at a wavelength of 2.1 cm.

Comment on whether it is possible to build an optical telescope operating at 580 nm that is to have the same resolution as the array.

It is proposed to build an array of radio telescopes such that the maximum distance between them is 3800 km. The array will operate at a wavelength of 2.1 cm.

Comment on whether it is possible to build an optical telescope operating at 580 nm that is to have the same resolution as the array.

It is proposed to build an array of radio telescopes such that the maximum distance between them is 3800 km. The array will operate at a wavelength of 2.1 cm.

Comment on whether it is possible to build an optical telescope operating at 580 nm that is to have the same resolution as the array.

Outline the formation of a B scan in medical ultrasound imaging.

Outline the formation of a B scan in medical ultrasound imaging.

Outline the formation of a B scan in medical ultrasound imaging.

State what is meant by half-value thickness in X-ray imaging.

State what is meant by half-value thickness in X-ray imaging.

State what is meant by half-value thickness in X-ray imaging.

A monochromatic X-ray beam of energy 20 keV and intensity I₀ penetrates 5.00 cm of fat and then 4.00 cm of muscle.

Calculate, in terms of I₀, the final beam intensity that emerges from the muscle.

A monochromatic X-ray beam of energy 20 keV and intensity I₀ penetrates 5.00 cm of fat and then 4.00 cm of muscle.

Calculate, in terms of I₀, the final beam intensity that emerges from the muscle.

A monochromatic X-ray beam of energy 20 keV and intensity I₀ penetrates 5.00 cm of fat and then 4.00 cm of muscle.

Calculate, in terms of I₀, the final beam intensity that emerges from the muscle.

Compare the use of high and low energy X-rays for medical imaging.

Compare the use of high and low energy X-rays for medical imaging.

Compare the use of high and low energy X-rays for medical imaging.

The diagram shows an incomplete ray diagram which consists of a red ray of light and a blue ray of light which are incident on a converging glass lens. In this glass lens the refractive index for blue light is greater than the refractive index for red light.

Using the diagram, outline the phenomenon of chromatic aberration.

The diagram shows an incomplete ray diagram which consists of a red ray of light and a blue ray of light which are incident on a converging glass lens. In this glass lens the refractive index for blue light is greater than the refractive index for red light.

Using the diagram, outline the phenomenon of chromatic aberration.

The diagram shows an incomplete ray diagram which consists of a red ray of light and a blue ray of light which are incident on a converging glass lens. In this glass lens the refractive index for blue light is greater than the refractive index for red light.

Using the diagram, outline the phenomenon of chromatic aberration.

Identify, with the letter X, the position of the focus of the primary mirror.

Identify, with the letter X, the position of the focus of the primary mirror.

Identify, with the letter X, the position of the focus of the primary mirror.

An optic fibre of refractive index 1.4475 is surrounded by air. The critical angle for the core – air boundary interface is 44°. Suggest, with a calculation, why the use of cladding with refractive index 1.4444 improves the performance of the optic fibre.

An optic fibre of refractive index 1.4475 is surrounded by air. The critical angle for the core – air boundary interface is 44°. Suggest, with a calculation, why the use of cladding with refractive index 1.4444 improves the performance of the optic fibre.

An optic fibre of refractive index 1.4475 is surrounded by air. The critical angle for the core – air boundary interface is 44°. Suggest, with a calculation, why the use of cladding with refractive index 1.4444 improves the performance of the optic fibre.

An amplifier can increase the power of the signal by 12 dB. Determine the minimum number of amplifiers required.

An amplifier can increase the power of the signal by 12 dB. Determine the minimum number of amplifiers required.

An amplifier can increase the power of the signal by 12 dB. Determine the minimum number of amplifiers required.

The graph shows the variation with wavelength of the refractive index of the glass from which the optic fibre is made.

Two light rays enter the fibre at the same instant along the axes. Ray A has a wavelength of λ_A and ray B has a wavelength of λ_B. Discuss the effect that the difference in wavelength has on the rays as they pass along the fibre.

The graph shows the variation with wavelength of the refractive index of the glass from which the optic fibre is made.

Two light rays enter the fibre at the same instant along the axes. Ray A has a wavelength of λ_A and ray B has a wavelength of λ_B. Discuss the effect that the difference in wavelength has on the rays as they pass along the fibre.

The graph shows the variation with wavelength of the refractive index of the glass from which the optic fibre is made.

Two light rays enter the fibre at the same instant along the axes. Ray A has a wavelength of λ_A and ray B has a wavelength of λ_B. Discuss the effect that the difference in wavelength has on the rays as they pass along the fibre.

In many places clad optic fibres are replacing copper cables. State one example of how fibre optic technology has impacted society.

In many places clad optic fibres are replacing copper cables. State one example of how fibre optic technology has impacted society.

In many places clad optic fibres are replacing copper cables. State one example of how fibre optic technology has impacted society.

calculate the linear magnification.

calculate the linear magnification.

calculate the linear magnification.

This arrangement using the secondary mirror is said to increase the focal length of the primary mirror. State why this is an advantage.

This arrangement using the secondary mirror is said to increase the focal length of the primary mirror. State why this is an advantage.

This arrangement using the secondary mirror is said to increase the focal length of the primary mirror. State why this is an advantage.

Distinguish between this mounting and the Newtonian mounting.

Distinguish between this mounting and the Newtonian mounting.

Distinguish between this mounting and the Newtonian mounting.

Identify whether the image is real or virtual.

Identify whether the image is real or virtual.

Identify whether the image is real or virtual.

The lens is 18 cm from the screen and the image is 0.40 times smaller than the object. Calculate the power of the lens, in cm^–1. 

The lens is 18 cm from the screen and the image is 0.40 times smaller than the object. Calculate the power of the lens, in cm^–1. 

The lens is 18 cm from the screen and the image is 0.40 times smaller than the object. Calculate the power of the lens, in cm^–1. 

Light passing through this lens is subject to chromatic aberration. Discuss the effect that chromatic aberration has on the image formed on the screen.

Light passing through this lens is subject to chromatic aberration. Discuss the effect that chromatic aberration has on the image formed on the screen.

Light passing through this lens is subject to chromatic aberration. Discuss the effect that chromatic aberration has on the image formed on the screen.

A system consisting of a converging lens of focal length F₁ (lens 1) and a diverging lens (lens 2) are used to obtain the image of an object as shown on the scaled diagram. The focal length of lens 1 (F₁) is 30 cm.

Determine, using the ray diagram, the focal length of the diverging lens.

A system consisting of a converging lens of focal length F₁ (lens 1) and a diverging lens (lens 2) are used to obtain the image of an object as shown on the scaled diagram. The focal length of lens 1 (F₁) is 30 cm.

Determine, using the ray diagram, the focal length of the diverging lens.

A system consisting of a converging lens of focal length F₁ (lens 1) and a diverging lens (lens 2) are used to obtain the image of an object as shown on the scaled diagram. The focal length of lens 1 (F₁) is 30 cm.

Determine, using the ray diagram, the focal length of the diverging lens.

Calculate the critical angle at the core−cladding boundary.

Calculate the critical angle at the core−cladding boundary.

Calculate the critical angle at the core−cladding boundary.

The use of optical fibres has led to a revolution in communications across the globe. Outline two advantages of optical fibres over electrical conductors for the purpose of data transfer.

The use of optical fibres has led to a revolution in communications across the globe. Outline two advantages of optical fibres over electrical conductors for the purpose of data transfer.

The use of optical fibres has led to a revolution in communications across the globe. Outline two advantages of optical fibres over electrical conductors for the purpose of data transfer.

Draw on the axes an output signal to illustrate the effect of waveguide dispersion.

Draw on the axes an output signal to illustrate the effect of waveguide dispersion.

Draw on the axes an output signal to illustrate the effect of waveguide dispersion.

Calculate the power of the output signal after the signal has travelled a distance of 3.40 km in the fibre.

Calculate the power of the output signal after the signal has travelled a distance of 3.40 km in the fibre.

Calculate the power of the output signal after the signal has travelled a distance of 3.40 km in the fibre.

Explain how the use of a graded-index fibre will improve the performance of this fibre optic system.

Explain how the use of a graded-index fibre will improve the performance of this fibre optic system.

Explain how the use of a graded-index fibre will improve the performance of this fibre optic system.

Hence state how the defect of the converging lens in (a) may be corrected.

Hence state how the defect of the converging lens in (a) may be corrected.

Hence state how the defect of the converging lens in (a) may be corrected.

Show that the longest path is 66 m longer than the shortest path.

Show that the longest path is 66 m longer than the shortest path.

Show that the longest path is 66 m longer than the shortest path.

Calculate n.

Calculate n.

Calculate n.

Calculate the distance between the lenses.

Calculate the distance between the lenses.

Calculate the distance between the lenses.

Determine the time delay between the arrival of signals created by the extra distance in (b)(i).

Determine the time delay between the arrival of signals created by the extra distance in (b)(i).

Determine the time delay between the arrival of signals created by the extra distance in (b)(i).

Determine the magnification of the microscope.

Determine the magnification of the microscope.

Determine the magnification of the microscope.

Determine, in terms of I₀, the intensity of ultrasound that is reflected at the muscle–bone boundary.

Determine, in terms of I₀, the intensity of ultrasound that is reflected at the muscle–bone boundary.

Determine, in terms of I₀, the intensity of ultrasound that is reflected at the muscle–bone boundary.

Ultrasound of intensity 50 mW m^-2 is incident on a muscle. The reflected intensity is 10 mW m^-2. Calculate the relative intensity level between the reflected and transmitted signals.

Ultrasound of intensity 50 mW m^-2 is incident on a muscle. The reflected intensity is 10 mW m^-2. Calculate the relative intensity level between the reflected and transmitted signals.

Ultrasound of intensity 50 mW m^-2 is incident on a muscle. The reflected intensity is 10 mW m^-2. Calculate the relative intensity level between the reflected and transmitted signals.

The image at I is the object for a second converging lens. This second lens forms a final image at infinity with an overall angular magnification for the two lens arrangement of 5. Calculate the distance between the two converging lenses.

The image at I is the object for a second converging lens. This second lens forms a final image at infinity with an overall angular magnification for the two lens arrangement of 5. Calculate the distance between the two converging lenses.

The image at I is the object for a second converging lens. This second lens forms a final image at infinity with an overall angular magnification for the two lens arrangement of 5. Calculate the distance between the two converging lenses.

A new object is placed a few meters to the left of the original lens. The student adjusts spacing of the lenses to form a virtual image at infinity of the new object. Outline, without calculation, the required change to the lens separation.

A new object is placed a few meters to the left of the original lens. The student adjusts spacing of the lenses to form a virtual image at infinity of the new object. Outline, without calculation, the required change to the lens separation.

A new object is placed a few meters to the left of the original lens. The student adjusts spacing of the lenses to form a virtual image at infinity of the new object. Outline, without calculation, the required change to the lens separation.

Explain the shape of the signal you sketched in (b)(ii).

Explain the shape of the signal you sketched in (b)(ii).

Explain the shape of the signal you sketched in (b)(ii).

A physician has a range of frequencies available for ultrasound. Comment on the use of higher frequency sound waves in an ultrasound imaging study.

A physician has a range of frequencies available for ultrasound. Comment on the use of higher frequency sound waves in an ultrasound imaging study.

A physician has a range of frequencies available for ultrasound. Comment on the use of higher frequency sound waves in an ultrasound imaging study.

Suggest the advantage in medical diagnosis of using ultrasound of frequency 1 MHz rather than 0.1 MHz.

Suggest the advantage in medical diagnosis of using ultrasound of frequency 1 MHz rather than 0.1 MHz.

Suggest the advantage in medical diagnosis of using ultrasound of frequency 1 MHz rather than 0.1 MHz.

Determine, in cm, the focal length of the objective lens.

Determine, in cm, the focal length of the objective lens.

Determine, in cm, the focal length of the objective lens.

Determine the distance at which the signal must be amplified.

Determine the distance at which the signal must be amplified.

Determine the distance at which the signal must be amplified.

Estimate the linear magnification of the image.

Estimate the linear magnification of the image.

Estimate the linear magnification of the image.

Explain chromatic aberration, with reference to your diagram in (b)(i).

Explain chromatic aberration, with reference to your diagram in (b)(i).

Explain chromatic aberration, with reference to your diagram in (b)(i).

Construct a ray diagram in order to locate the position of the image formed by the mirror. Label the image $\text{I}$.

Construct a ray diagram in order to locate the position of the image formed by the mirror. Label the image $\text{I}$.

Construct a ray diagram in order to locate the position of the image formed by the mirror. Label the image $\text{I}$.

Calculate, in cm, the distance between the eyepiece and the image formed by the objective lens.

Calculate, in cm, the distance between the eyepiece and the image formed by the objective lens.

Calculate, in cm, the distance between the eyepiece and the image formed by the objective lens.

In nuclear magnetic resonance (NMR) protons inside a patient are made to emit a radio frequency electromagnetic radiation. Outline the mechanism by which this radiation is emitted by the protons.

In nuclear magnetic resonance (NMR) protons inside a patient are made to emit a radio frequency electromagnetic radiation. Outline the mechanism by which this radiation is emitted by the protons.

In nuclear magnetic resonance (NMR) protons inside a patient are made to emit a radio frequency electromagnetic radiation. Outline the mechanism by which this radiation is emitted by the protons.

State and explain, with reference to you answer in (a)(i), what needs to be done to produce a clear image of the leg artery using X-rays.

State and explain, with reference to you answer in (a)(i), what needs to be done to produce a clear image of the leg artery using X-rays.

State and explain, with reference to you answer in (a)(i), what needs to be done to produce a clear image of the leg artery using X-rays.

Show that the ratio $\frac{I_{\mathrm{b}}}{I_{\mathrm{t}}}$ is close to 1.

Show that the ratio $\frac{I_{\mathrm{b}}}{I_{\mathrm{t}}}$ is close to 1.

Show that the ratio $\frac{I_{\mathrm{b}}}{I_{\mathrm{t}}}$ is close to 1.

When the Earth-Moon distance is 363 300 km, the Moon is observed using the telescope. The mean radius of the Moon is 1737 km. Determine the focal length of the mirror used in this telescope when the diameter of the Moon’s image formed by the main mirror is 1.20 cm.

When the Earth-Moon distance is 363 300 km, the Moon is observed using the telescope. The mean radius of the Moon is 1737 km. Determine the focal length of the mirror used in this telescope when the diameter of the Moon’s image formed by the main mirror is 1.20 cm.

When the Earth-Moon distance is 363 300 km, the Moon is observed using the telescope. The mean radius of the Moon is 1737 km. Determine the focal length of the mirror used in this telescope when the diameter of the Moon’s image formed by the main mirror is 1.20 cm.

determine the focal length of the lens.

determine the focal length of the lens.

determine the focal length of the lens.

Suggest how the refracted rays in (a) are modified when the converging lens is replaced by a diverging lens.

Suggest how the refracted rays in (a) are modified when the converging lens is replaced by a diverging lens.

Suggest how the refracted rays in (a) are modified when the converging lens is replaced by a diverging lens.

Describe how the measurement in (b) provides diagnostic information for the doctor.

Describe how the measurement in (b) provides diagnostic information for the doctor.

Describe how the measurement in (b) provides diagnostic information for the doctor.

Determine, by calculation, the linear magnification produced in the above diagram.

Determine, by calculation, the linear magnification produced in the above diagram.

Determine, by calculation, the linear magnification produced in the above diagram.

The acoustic impedance of soft tissue is 1.65 × 106 kg m^-2 s^-1. Show that the speed of sound in the soft tissue is approximately 1500 m s^–1.

The acoustic impedance of soft tissue is 1.65 × 106 kg m^-2 s^-1. Show that the speed of sound in the soft tissue is approximately 1500 m s^–1.

The acoustic impedance of soft tissue is 1.65 × 106 kg m^-2 s^-1. Show that the speed of sound in the soft tissue is approximately 1500 m s^–1.

In the ultrasound scan the frequency is chosen so that the distance between the transducer and the organ is at least 200 ultrasound wavelengths. Estimate, based on your response to (b)(ii), the minimum ultrasound frequency that is used.

In the ultrasound scan the frequency is chosen so that the distance between the transducer and the organ is at least 200 ultrasound wavelengths. Estimate, based on your response to (b)(ii), the minimum ultrasound frequency that is used.

In the ultrasound scan the frequency is chosen so that the distance between the transducer and the organ is at least 200 ultrasound wavelengths. Estimate, based on your response to (b)(ii), the minimum ultrasound frequency that is used.

A parallel beam of X-rays travels through 7.8 cm of tissue to reach the bowel surface. Calculate the fraction of the original intensity of the X-rays that reach the bowel surface. The linear attenuation coefficient for tissue is 0.24 cm^–1.

A parallel beam of X-rays travels through 7.8 cm of tissue to reach the bowel surface. Calculate the fraction of the original intensity of the X-rays that reach the bowel surface. The linear attenuation coefficient for tissue is 0.24 cm^–1.

A parallel beam of X-rays travels through 7.8 cm of tissue to reach the bowel surface. Calculate the fraction of the original intensity of the X-rays that reach the bowel surface. The linear attenuation coefficient for tissue is 0.24 cm^–1.

The fluid in the bowel has a similar linear attenuation coefficient as the bowel surface. Gases have much lower linear attenuation coefficients than fluids. Explain why doctors will fill the bowel with air before taking an X-ray image.

The fluid in the bowel has a similar linear attenuation coefficient as the bowel surface. Gases have much lower linear attenuation coefficients than fluids. Explain why doctors will fill the bowel with air before taking an X-ray image.

The fluid in the bowel has a similar linear attenuation coefficient as the bowel surface. Gases have much lower linear attenuation coefficients than fluids. Explain why doctors will fill the bowel with air before taking an X-ray image.

Draw on the diagram the three wavefronts after they have passed through the lens.

Draw on the diagram the three wavefronts after they have passed through the lens.

Draw on the diagram the three wavefronts after they have passed through the lens.

Lens A has a focal length of $4.00 \mathrm{cm}$. An object is placed $4.50 \mathrm{cm}$ to the left of A. Show by calculation that a screen should be placed about $0.4 \mathrm{m}$ from A to display a focused image.

Lens A has a focal length of $4.00 \mathrm{cm}$. An object is placed $4.50 \mathrm{cm}$ to the left of A. Show by calculation that a screen should be placed about $0.4 \mathrm{m}$ from A to display a focused image.

Lens A has a focal length of $4.00 \mathrm{cm}$. An object is placed $4.50 \mathrm{cm}$ to the left of A. Show by calculation that a screen should be placed about $0.4 \mathrm{m}$ from A to display a focused image.

The screen is removed and the image is used as the object for a second diverging lens B, to form a final image. Lens B has a focal length of $2.00 \mathrm{cm}$ and the final real image is $8.00 \mathrm{cm}$ from the lens. Calculate the distance between lens A and lens B.

The screen is removed and the image is used as the object for a second diverging lens B, to form a final image. Lens B has a focal length of $2.00 \mathrm{cm}$ and the final real image is $8.00 \mathrm{cm}$ from the lens. Calculate the distance between lens A and lens B.

The screen is removed and the image is used as the object for a second diverging lens B, to form a final image. Lens B has a focal length of $2.00 \mathrm{cm}$ and the final real image is $8.00 \mathrm{cm}$ from the lens. Calculate the distance between lens A and lens B.

Calculate the total magnification of the object by the lens combination.

Calculate the total magnification of the object by the lens combination.

Calculate the total magnification of the object by the lens combination.

Outline the meaning of normal adjustment for a compound microscope.

Outline the meaning of normal adjustment for a compound microscope.

Outline the meaning of normal adjustment for a compound microscope.