P3.1

Question 1

Difference between ultrasound waves and xrays

Answer 1

Ultrasound waves are non-ionising and X-rays are ionising

Question 2

Properties of X-rays

Answer 2

They affect a photographic film the same way as light

They are absorbed by metal and bone

They are transmitted by soft tissue

Their wavelength is of the same order of magnitude as the diameter of an atom

Question 3

What spectrum are X-rays a part of

Answer 3

Electromagnetic spectrum

Question 4

Are X-rays wavelength short or long

Answer 4

Short

Question 5

What do xrays cause

Answer 5

Ionisation

Question 6

What 5things can X-rays be used for

Answer 6

Diagnose and treat medical conditions
CT scans
Killing cancer cells
Bone fractures 
Dental problems

Question 7

What does the use of charge-coupled devices(CCDs) allow

Answer 7

Images to be formed electronically

Question 8

What needs to be taken when X-rays and CT scanners are in use

Answer 8

Precautions

Question 9

What is the range for human hearing

Answer 9

200 to 20,000 Hz

Question 10

What can electronic systems to produce

Answer 10

Ultrasound waves

Question 11

What frequency do ultrasound waves have

Answer 11

A frequency higher than the upper limit of hearing for humans

Question 12

When are ultrasound waves partially reflected

Answer 12

When they meet a boundary between two different media

Question 13

What can the taken for the reflections to reach a detector be used to determine

Answer 13

How far away such a boundary is

Question 14

What can ultrasound be used in and for what

Answer 14

In medicine

Pre natal scanning
Removal of kidney stones

Question 15

What is refraction

Answer 15

The change of direction of light as it passes from one medium to another

Question 16

How does a lens form an image

Answer 16

Refracting light

Question 17

What happens in convex or converging lens

Answer 17

Parallel rays of light are brought to a focus at the principal focus

Question 18

What is the focal length

Answer 18

The distance from the lens to the principal focus

Question 19

How is the nature of an image defined by

Answer 19

Its size relative to the object

Whether it is upright or inverted relative to the object

Whether it is real or virtual

Question 20

What is a use of converging lens

Answer 20

Magnifying glass

Question 21

What is in a eye

Answer 21

Retina
Lens
Cornea
Pupil/ iris
Ciliary muscle
Suspensory ligaments

Question 22

What is being long sighted caused by

Answer 22

The eyeball is too short or the eye lens being unable to focus

Question 23

What is being short sighted caused by

Answer 23

The eyeball being to long or the eye lens being unable to focus

Question 24

What is the range of vision

Answer 24

Between the near point and the far point

Question 25

The length of the near point

Answer 25

25cm

Question 26

The length of the far point

Answer 26

Infinity

Question 27

What is equivalent to the retina in the eye

Answer 27

The film in a camera or the CCDs in a digital camera

Question 28

The power of what is positive

Answer 28

The power of a converging lens

Question 29

The power of what is negative

Answer 29

The power of a diverging lens

Question 30

What is the focal length determined by

Answer 30

The refractive index of the material from which the lens is made The curvature of the two surfaces of the lens

Question 31

For a given focal length, the greater the refractive index...... and what does it means

Answer 31

The flatter the length It means that the lens can be manufactured thinner

Question 32

Examples of the use for visible light

Answer 32

Endoscope for internal imaging

Question 33

What can visible light be sent along

Answer 33

Optical fibres

Question 34

What are lasers

Answer 34

Qn energy source for cutting, cauterising, burning and eye surgery