Using reflection and refraction

Question 1

what are optical fibres

Answer 1

thin glass fibres that are used to transmit digital data in the form of pulses of light. the light travels along the fibres by total internal reflection

Question 2

explain total internal reflection in optical fibres

Answer 2

rays of light meeting the boundary between the cladding and the core are totally internally reflected

Question 3

explain the conditions necessary for total internal reflection to take place

Answer 3

1) cladding must have a smaller refractive index than the core
2) the waves must meet the boundary at an angle greater than the critical angle.

Question 4

what are endoscopes used for, what do they allow

Answer 4

used to look inside patients bodies, and make use of optical fibres. endoscopes allow keyhole surgery. this is surgery conducted through a very small cut in the body to speed up recovery time

Question 5

what is ultrasound

Answer 5

sound with a much higher frequency that can be heard by humans. it can travel through human tissue without causing damage, so it is used to scan the body. some ultrasound is reflected whenever there is a change in the speed of the ultrasound waves.

Question 6

explain the uses of ultrasound

Answer 6

used to break up stones that form in parts of the body without the need for surgery. also used to treat muscle and other soft tissue injuries by focusing energy on the specific injury location.