All EM waves travel at 3 ร 10โธ m/s in a vacuum. All are transverse.
Order (low freq/long ฮป โ high freq/short ฮป): Radio, Microwave, Infrared, Visible, UV, X-ray, Gamma.
MNEMONIC: Roman Men Invented Very Useful X-ray Gums.
Higher frequency = more energy = more dangerous.
Uses: radio (communication), microwave (cooking/comms), IR (heaters/remote controls), visible (sight), UV (sterilising/sunbeds), X-ray (medical imaging), gamma (cancer treatment/sterilising).
Exam questions โ 4 questions ยท 12 marks
โก Extended questions included. Show all working for calculation questions. The AI marks against the real AQA mark scheme.
1 markWave equationAQA 8463 P2 style
A wave has a frequency of 200 Hz and a wavelength of 1.5 m. What is its speed?
A 133 m/s
B 200 m/s
C 300 m/s
D 0.0075 m/s
3 marksEM spectrum propertiesAQA 8463 P2 style
State the order of the electromagnetic spectrum from longest to shortest wavelength. Give one use for each end of the spectrum. (3 marks)
Hint: Low frequency = long wavelength. Radio โ Micro โ IR โ Visible โ UV โ X โ Gamma.
+30 XP
4 marksRefraction explanationAQA 8463 P2 style
A ray of light passes from air into a glass block at an angle. Explain what happens to the speed, wavelength and direction of the light as it enters the glass. (4 marks)
Hint: Speed changes โ wavelength changes (same frequency). Speed decreases โ bends towards normal. Cover all three: speed, wavelength, direction.