Pulse oximeters and ECGs are used to monitor the blood oxygen levels and heart activity of a patient - Edexcel - GCSE Physics - Question 6 - 2015 - Paper 1
Question 6
Pulse oximeters and ECGs are used to monitor the blood oxygen levels and heart activity of a patient.
(a) Pulse oximeters are often attached to a finger.
They use b... show full transcript
Worked Solution & Example Answer:Pulse oximeters and ECGs are used to monitor the blood oxygen levels and heart activity of a patient - Edexcel - GCSE Physics - Question 6 - 2015 - Paper 1
Step 1
A infrared radiation is ionising, red light is not ionising
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This statement is correct. Infrared radiation is non-ionising, meaning it does not carry enough energy to remove tightly bound electrons from atoms, whereas red light is also non-ionising.
Step 2
B red light can travel through a finger, infrared cannot travel through a finger
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This statement is incorrect. Both red light and infrared can travel through a finger, but infrared light penetrates deeper into biological tissues.
Step 3
C red light has a shorter wavelength than infrared
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This statement is correct. Red light has a shorter wavelength (approximately 620-750 nm) than infrared light (greater than 750 nm), thus placing it higher on the electromagnetic spectrum.
Step 4
D red light is ionising, infrared is not ionising
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This statement is incorrect. Both red light and infrared are non-ionising radiations.
Step 5
b) A student investigates absorption of light.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
From the results, it can be observed that as the thickness of the absorber increases, the intensity of light detected decreases. This indicates that thicker absorbers are more effective at absorbing light, supporting the principle that increased material thickness leads to greater light absorption.
