P6: Quiz 6 – Answers
1)
a) EM waves are transverse. Transverse waves have oscillations that are perpendicular to the direction of travel
b) Yes – EM waves travel at the same speed. They travel at 300 million metres per second, which is 3 x 108 m/s
2) Electric, magnetic fields
Electromagnetic (EM) waves are made up of oscillating ELECTRIC and MAGNETIC FIELDS.
3)
a)
1 = radio waves
2 = microwaves
3 = infrared
4 = visible light
5 = ultraviolet
6 = X-rays
7 = gamma rays
b) Frequency increases
4)
a) red
b) violet
c) violet
d) red
5) The sun emits infrared radiation – the sun is the source. When your phone is left out in the sun, the phone’s screen absorbs infrared radiation from the sun, which results in energy being transferred to the thermal energy stores of the phone, thus causing the phone to become hot
1)
a) Are electromagnetic waves transverse or longitudinal? Also, give the definition of the type of wave that they are.
b) Do all electromagnetic waves travel at the same speed? If so, what speed do they travel at through a vacuum?
2) Fill in the gaps in the sentence below.
Electromagnetic (EM) waves are made up of oscillating ______ and ______ ______.
3) The electromagnetic spectrum is split into 7 different groups. The diagram below shows the 7 different groups with the waves on the left having the longest wavelength and the waves on the right having the shortest wavelength.
b) As we go from left to right, what happens to the frequency of the waves; does the frequency increase or decrease?
4) Visible light is the only part of the electromagnetic spectrum that we can see.
a) Within visible light, which colour has the longest wavelength?
b) Within visible light, which colour has the shortest wavelength?
c) Within visible light, which colour has the highest frequency?
d) Within visible light, which colour has the lowest frequency?
5) Explain why a phone becomes hot when it is left out in the sun on a very sunny day. Talk about the source, the absorber and the energy transfers taking place.