Edexcel Further Additonal Science Topic P3.1 Radiation in Treatment and Medicine Test 12_13

TEST 3 – PART A

YEAR 5 TRIPLE SCIENCE PHYSICS 1 Turn over

Surname

Name

American Academy Larnaca

Year 5 Physics

Semester 2

Test 3

Unit P3

Applications of Physics

Topic 1 Radiation in treatment and medicine Monday 21 October 2012 Part A

Time: 20 minutes

• The total marks for this part is 20. • The total marks for the paper is 40. • The marks for each question are shown in square brackets.

Use this as a guide as to how much time to spend on each question. • Questions labelled with an asterisk (*) are ones where the quality of your written communication

will be assessed. You should take particular care with your spelling and grammar, as well as the clarity of expression, on these questions.

• Answer the questions in the spaces provided. There may be more space than you need.

TEST 3 – PART A


FORMULAE

You may find theses formulae useful

The relationship between focal length, object and image distance

current = number of particles per second × charge on each particle I = N × q

kinetic energy = electronic charge × accelerating potential difference

momentum = mass × velocity p = m × v

The relationship between temperature and volume for a gas

The relationship between volume and pressure for a gas V1 P1 = V2 P2

The relationship between the volume, pressure and temperature for a gas

Do not forget to include units in all your answers.

TEST 3 – PART A


_______________________________________________________________________________________ 1. Light moves from one medium to another as shown in the diagram below.

(a) Put a cross ( ) in the box next to the correct answer.

[1 mark] Which is correct about the speed of light in the two media?

A Light is faster in medium 1

B Light is faster in medium 2

C Light has the same speed in both media

D T ’ m m

(b) Which medium, 1 or 2, has the largest refractive index?

Explain briefly. [2 marks]

……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… (c) Put a cross ( ) in the box next to the correct answer.

[1 mark] Which formula correctly b ’ L m ?

A n1 sin y = n2 sin w

B n1 sin y = n2 sin x

C n1 sin z = n2 sin w

D n1 sin z = n2 sin x

medium 1

medium 2 x

y

w

z refractive index n1

refractive index n2

TEST 3 – PART A


(d) The diagram below shows light wavefronts as they move from medium 1 to medium 2.

Describe how wavelength and frequency change as light moves from medium 1 to medium 2.

[2 marks] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………

[Total for Question 1 = 6 marks] _______________________________________________________________________________________

medium 1

medium 2

TEST 3 – PART A


_______________________________________________________________________________________ 2. (a) Below you can see the diagram of an eye.

(i) Write the letter (P − U) that represents each of the following structures.

[2 marks]

O ………………………… C ………………………… (ii) Write the letters (P − U) of the two structures responsible for focusing light on the retina.

[1 mark]

………………………… and ………………………… (b) What is the function of the iris?

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… (c) Explain the importance of the ciliary muscles.

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………


P

Q

R

S

T

U

TEST 3 – PART A


3. (a) Mark has an eyesight problem.

He cannot focus on an object if it is closer than 50 cm. (i) W m b b M k’ ?

Is it short sight or long sight? [1 mark]

Figure 1 Figure 2

……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… (ii) D b M k’ .

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… (iii) The doctor must restore conditions for an average person.

He suggests that Mark uses glasses. He prescribes a lens so that an object 25 cm away will have a virtual image at 50 cm. This will then allow the eye to detect an object at a closer distance. Calculate the focal length and power of the lens the doctor prescribes. What type of lens is Mark prescribed? Be careful with units.

[3 marks]

F …………………………

P …………………………

T ……………………………………………………

TEST 3 – PART A

YEAR 5 TRIPLE SCIENCE PHYSICS 7

* (b) Other techniques that Mark could choose from to correct his vision include contact lenses and

laser correction. Describe the advantages and disadvantages of each of these methods and give a possible reason why Mark preferred glasses instead.

[4 marks] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………


TOTAL FOR PART A = 20 MARKS _______________________________________________________________________________________

END TOTAL FOR PAPER = 40 MARKS

TEST 3 – PART B


Surname

Name

American Academy Larnaca

Year 5 Physics

Semester 2

Test 4

Unit P3

Applications of Physics

Topic 1 Radiation in treatment and medicine Monday 21 October 2012 Part B

Time: 20 minutes

• The total marks for this part is 20. • The total marks for the paper is 40. • The marks for each question are shown in square brackets.

Use this as a guide as to how much time to spend on each question. • Questions labeled with an asterisk (*) are ones where the quality of your written communication

will be assessed. You should take particular care with your spelling and grammar, as well as the clarity of expression, on these questions.

• Answer the questions in the spaces provided. There may be more space than you need.

TEST 3 – PART B


FORMULAE

You may find theses formulae useful

The relationship between focal length, object and image distance

current = number of particles per second × charge on each particle I = N × q

kinetic energy = electronic charge × accelerating potential difference

momentum = mass × velocity p = m × v

The relationship between temperature and volume for a gas

The relationship between volume and pressure for a gas V1 P1 = V2 P2

The relationship between the volume, pressure and temperature for a gas

Do not forget to include units in all your answers.

TEST 3 – PART B


_______________________________________________________________________________________ 1. The diagram below shows how light is reflected from a mirror.

The image is formed from light reflected not from the outer glass surface but from the silver coating on the inner glass surface.

(a) Calculate the angle of refraction r.

[2 marks]

A ………………………… (b) Continue the light ray to show how it emerges from the mirror.

Do not forget to draw the normal lines where appropriate. [2 marks]

(c) Put a cross ( ) in the box next to the correct answer.

[1 mark] The angle, with respect to the normal, that light emerges from the mirror is

A 30°

B 40°

C 50°

D 60°

[Total for Question 1 = 5 marks]

_______________________________________________________________________________________

outer glass surface

inner silver coating

refractive index n = 1.5

50°

r

TEST 3 – PART B


_______________________________________________________________________________________ 2. Movie projectors use lenses to focus the pictures on the film (object) onto a large screen

creating a real image. (a) Below you see a simple arrangement of a convex lens and an object.

F represents the focus of the lens.

(i) Complete the drawing above by continuing the rays going through the lens.

Show how the image will appear. [2 marks]

(ii) The object is 30 cm away from the lens.

The focal length of the lens is 20 cm. Calculate the distance from the lens at which the image will appear.

[2 marks]

D m m ………………………… (iii) Describe the image.

Is it larger or smaller than the object? Is it upside down or right way up?

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………

F

20 cm 30 cm

TEST 3 – PART B


(b) Explain how in a movie theatre the image (movie) appears the right way up.

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… (c) The movie in a movie theatre is projected on a large screen.

The image on the screen is much larger than the object on the film. Suggest a possible way that this is achieved.

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………


TEST 3 – PART B


_______________________________________________________________________________________ 3. Endoscopes use an external light source to illuminate organs.

Light moves through optical fibres by total internal reflection.

(a) The optical fibre is made of high transparency glass. (i) The refractive index of this glass with respect to air is equal to

nglass = 1.41, nair = 1 Show that the critical angle between glass and air is 45°.

[1 mark] (ii) Put a cross ( ) in the box next to the correct answer.

[1 mark] To achieve total internal reflection the light ray should strike the glass surface at an angle of

incidence equal to

A 35°

B 40°

C 45°

D 50°

(b) The optical fibre has an area of 4 × 10–5 (0.00004) m2.

The light source gives a power of 0.2 W. Calculate the light intensity through the optical fibre.

[2 marks]

I …………………………

tissue light source

optical fibres

TEST 3 – PART B


* (c) Biopsy is a procedure in which cells are removed from tissues inside the body or from the skin.

To remove the cells doctors use various techniques, including small scale surgery. Sometimes doctors use endoscopic forceps, like the ones shown below, to remove cells from internal surfaces, especially the stomach and intestines.

The cells are then studied under the microscope or undergo chemical tests for an accurate diagnosis. Compare the method of optical endoscopy and biopsy referring to the advantages and disadvantages of the two methods. Explain why doctors will perform optical endoscopy whenever possible and use biopsy when absolutely necessary.

[4 marks] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………


TOTAL FOR PART B = 20 MARKS _______________________________________________________________________________________

END TOTAL FOR PAPER = 40 MARKS

TEST 3 – MARK SCHEME – PART A


MARK SCHEME

PART A

p. 3 & 4 1. (a) B [1 mark] (b) n1 > n2 (or similar) [1 mark]

& Any one from [1 mark] Light bends away from normal Light is faster in medium 1 / slower in medium 2 [accept some reference to change in speed] Angle of refraction > Angle of incidence etc.

(c) A [1 mark] (d) Frequency constant etc. [1 mark]

Wavelength increases [1 mark] m “W ” [ / m k]

p. 5 2. (a) (i) Optic nerve = P [1 mark]

Cornea = S [1 mark] (ii) Cornea / S [1/2 mark]

Lens / U [1/2 mark] (b) Any one from [1 mark]

Changes the size of the pupil Controls the amount of light entering the eye Larger / Wider in bright light and smaller / thinner in darker conditions etc.

(c) Change the size / thickness of the lens (or similar) [1/2 mark]

& And any one from [1/2 mark] To focus image on retina To have a clear image on retina To be able to see close and far away (objects) clearly etc. To refract light less/more

TEST 3 – MARK SCHEME – PART A


p. 6 & 7 3. (a) (i) Figure 1 [1/2 mark]

Long sight [1/2 mark] (ii) Any one from [1 mark]

Too short eyeball Lens to stiff [due to aging] / cornea not curved enough

(iii) u = 0.25 m, v −0.5 m & − v [1/2 mark]

0. 5

-0.5 formula &/V substitution [1/2 mark]

=> f = 0.5 m, P = 2 D calculation (allow for ecf) [1 mark] both units [1/2 mark] Accept if units not converted from start => f = 50 cm There must be a unit conversion before calculating Power Convex / Converging (accept drawing) [1/2 mark]

* (b) Contact lenses

Advantages Aesthetic

No need to carry around / Will not forget etc.

Disadvantages Needs to be removed daily Needs to be taken care of

Laser correction Advantages

Provides permanent solution Disadvantages Cost &/V time to complete procedure Invasive / Requires surgery More elaborate procedure Possible psychological barrier

Any of the disadvantages from each method as a reason for Mark choosing glasses instead Level Marks 1 1 – 2 Gives an advantage of each method

OR Gives an advantage of one method and one disadvantage OR Gives s disadvantage for each method

2 3 − 4 Discusses advantages and disadvantages of each method Clearly refers to why Mark would prefer glasses instead

TEST 3 – MARK SCHEME – PART B


MARK SCHEME

PART B

p. 3 1. (a) n = sin i / sin r formula [1/2 mark]

1.5 = sin 50 / sin r [1/2 mark] r = sin−1 (sin 50 / 1.5) rearrangement of previous expression [1/2 mark] r = 30.7° = 30° = 31° calculation [1/2 mark]

(b)

(c) C [1 mark]

normal [1/2 mark]

normal [1/2 mark]

reflected ray by eye [1/2 mark] angle of incidence = angle of reflection

refracted ray [1/2 mark] bending away from normal



p. 4 & 5 2. (a) (i)

(ii)

0

0

formula &/V substitution [1/2 mark]

0 -

0 rearrangement [1/2 mark]

=> v = 60 cm calculation (allow for ecf) [1/2 mark] unit [1/2 mark] (iii) Larger [1/2 mark]

Upside down [1/2 mark] (b) Object / Film is placed upside down (or similar) [1 mark]

[Accept another lens used to invert image again.] (c) Any one from [1 mark]

Object / Film closer to lens Focal length is larger / Focus further away (or similar)

F

continue ray straight [1/2 mark]

pass ray through focus [1/2 mark]

draw image in correct size & position [1/2 mark] upside down [1/2 mark]



p. 6 & 7 3. (a) (i) n1 sin θ1 = n2 sin θ2 => 1 × sin c = 1.41 × sin 90° formula &/V substitution [1/2 mark]

c = sin−1(1/1.41) = 45.2° calculation (allow for ecf) [1/2 mark] (ii) D [1 mark] (b) I = P / A formula [1/2 mark]

I = 0.2 / (4 × 10−5) substitution [1/2 mark] I = 5000 W/m2 calculation [1/2 mark] unit [1/2 mark]

* (c) Optical spectroscopy

Advantages Simple / Fast

Non-invasive (or to that effect) Immediate results

Disadvantages Cannot reveal complicated problems

Endoscopic biopsy Advantages

More detailed diagnosis Disadvantages Requires surgery / cutting Interferes with the working of the body Takes longer to give results

Doctors will prefer optical endoscopy because it is faster and non-invasive or any other of the advantages mentioned above

Level Marks 1 1 – 2 May refer to an advantage or a disadvantage of one of the methods

May refer to an advantage of both methods May refer to a disadvantage of both methods Allow for advantages / disadvantages not mentioned above

2 3 − 4 Refers to an advantage &/V disadvantage for one method Refers to more than one advantage &/V disadvantage for second method Allow for advantages / disadvantages not mentioned above Relates advantages &/V disadvantages to preference for optical endoscopy

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Edexcel Further Additonal Science Topic P3.1 Radiation in Treatment and Medicine Test 12_13