[Maximum number: 4]

This question is about the eye and sight.

(a)

Green light is shone onto a yellow filter. State the colour of the light that is transmitted through the filter.

[ 1 ]

(b)

(i)

A white object is illuminated with equal intensities of red light and green light at the same time. State the colour that the object will appear to an observer.

[ 1 ]

(ii)

Another white object is viewed in bright sunlight. Outline, with reference to the light-sensitive cells on the retina, why the object is seen more clearly when viewed directly rather than from the corner of the eye.

[ 2 ]

[Maximum number: 5]

This question is about the eye.

(a)

Explain, with reference to spectral response, why the eye has poor colour sensitivity under scotopic vision.

[ 3 ]

(b)

Outline how the distribution of retinal cells in the eye accounts for differences in perception.

[ 2 ]

[Maximum number: 2]

A radio wave of wavelength $\lambda$ is incident on a conductor. The graph shows the variation with wavelength $\lambda$ of the maximum distance d travelled inside the conductor.

(a)

The graph shows the variation with wavelength $\lambda$ of $d^{2}$ . Error bars are not shown and the line of best-fit has been drawn.

A student states that the equation of the line of best-fit is $d^{2}=a+b \lambda$ . When $d^{2}$ and $\lambda$ are expressed in terms of fundamental SI units, the student finds that $a=0.040 \times 10^{-4}$ and $b=1.8 \times 10^{-11}$ .

[ 2 ]

(i)

Determine the distance travelled inside the conductor by very high frequency electromagnetic waves.

[ 2 ]

[Maximum number: 2]

A radio wave of wavelength $\lambda$ is incident on a conductor. The graph shows the variation with wavelength $\lambda$ of the maximum distance d travelled inside the conductor.

(a)

The graph shows the variation with wavelength $\lambda$ of $d^{2}$ . Error bars are not shown and the line of best-fit has been drawn.

A student states that the equation of the line of best-fit is $d^{2}=a+b \lambda$ . When $d^{2}$ and $\lambda$ are expressed in terms of fundamental SI units, the student finds that $a=0.040 \times 10^{-4}$ and $b=1.8 \times 10^{-11}$ .

[ 2 ]

(i)

Determine the distance travelled inside the conductor by very high frequency electromagnetic waves.

[ 2 ]

[Maximum number: 1]

What is the order of magnitude of the wavelength of visible light?

A

$10^{-10} \mathrm{~m}$

B

$10^{-7} \mathrm{~m}$

C

$10^{-4} \mathrm{~m}$

D

$10^{-1} \mathrm{~m}$

[Maximum number: 1]

What is a possible wavelength of a visible light photon?

A

$500 \mu \mathrm{~m}$

B

500 nm

C

$50 \mu \mathrm{~m}$

D

50 nm

[Maximum number: 3]

Student A conducts an experiment to determine the speed of sound in air using tubes of different lengths. Each tube is open at one end and closed at the other end.

A short pulse of sound is produced by a loudspeaker near the open end of each tube. A microphone is placed at the open end of each tube and detects the sound entering and leaving the tube.

The graph shows the variation with tube length L of the time t for the sound to travel along the tube and be reflected back.

The percentage uncertainty in each time measurement is 9 %. The uncertainty in L is negligible.

(a)

Determine, using the graph, the speed of sound. State an appropriate unit for your answer.

[ 3 ]

[Maximum number: 3]

Student A conducts an experiment to determine the speed of sound in air using tubes of different lengths. Each tube is open at one end and closed at the other end.

A short pulse of sound is produced by a loudspeaker near the open end of each tube. A microphone is placed at the open end of each tube and detects the sound entering and leaving the tube.

The graph shows the variation with tube length L of the time t for the sound to travel along the tube and be reflected back.

The percentage uncertainty in each time measurement is 9 %. The uncertainty in L is negligible.

(a)

Determine, using the graph, the speed of sound. State an appropriate unit for your answer.

[ 3 ]

[Maximum number: 5]

A1. This question is about colour vision.
(a) State which type of receptor cell in the eye is responsible for detection of colour.
(b) The graph below shows how absorption varies with wavelength for the three types of colour receptor.

(i) Identify the colours that the receptors are sensitive to.

Receptor A:
Receptor B:
Receptor C:
(ii) Red-green colour blindness is more common than red-blue colour blindness. Using the information on the graph suggest why this is the case.
(iii) State which of the receptors absorb yellow light.

(a)

Outline what is meant by additive colour mixing.

[ 1 ]

(b)

The graph shows the variation with wavelength of light absorption for the red-sensitive cone cells of a normal eye.

light absorption / arbitrary units

Aibhe has colour blindness with reduced quantities of pigment in her red-sensitive cones.

[ 5 ]

(i)

Sketch on the graph the light absorption curve of the red-sensitive cones for Aibhe.

[ 2 ]

(ii)

State and explain the difference in the perceived colour, between Aibhe and a person with normal colour vision, when observing a magenta (purple) object in white light.

[ 3 ]