Skip to content
QuizQuip
Sign up
Back to Topic 9
Question paperPDF

Topic 9 Practice Paper: Electromagnetic spectrum — mark scheme

QuizQuipPractice Series
QQ/IGCSE-PHYS/T9

IGCSE · Cambridge IGCSE Physics (Extended (Core + Supplement))

Mark scheme

Electromagnetic spectrum

Topic 9 Practice Paper · Maximum mark: 30

Notes for markers

  • Award one mark for each point marked [1], up to the marks shown for the part.
  • Accept answers worded differently that show the same understanding.
  • Units are required where the answer line shows one. ecf: allow an error carried forward.

Section A: Multiple-choice questions[10 marks]

QuestionAnswer and marking pointsMarks
Total for Question 11
Total for Question 21
Total for Question 31
Total for Question 41
Total for Question 51
Total for Question 61
Total for Question 71
Total for Question 81
Total for Question 91
Total for Question 101

Section B: Structured questions[20 marks]

QuestionAnswer and marking pointsMarks
11(a)

Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, gamma rays.

  • radio → microwaves → infrared → visible → ultraviolet → X-rays in order [1]
  • gamma rays last [1]
2
11(b)

It decreases — wavelength and frequency vary inversely because all the waves share one speed.

  • wavelength decreases [1]
1
11(c)

All travel at 3.0 × 10⁸ m/s in a vacuum.

  • 3.0 × 10⁸ m/s [1]
1
11(d)

They are all transverse waves (and none needs a medium).

  • transverse / no medium needed [1]
1
Total for Question 115
12(a)

Gamma rays: they are highly penetrating and kill bacteria and other microorganisms on equipment, even through packaging.

  • gamma rays [1]
  • kill microorganisms / penetrate packaging [1]
2
12(b)

X-rays; they are ionising and can mutate or damage cells in the body, so staff must minimise exposure.

  • X-rays [1]
  • mutation / cell damage hazard [1]
2
12(c)

Uses: security marking, detecting fake bank notes or sterilising water. Precautions: sunscreen, sunglasses, limiting sunbathing time.

  • valid UV use [1]
  • valid precaution [1]
2
Total for Question 126
13(a)

The satellite is geostationary: it orbits with Earth’s rotation, so it stays above the same point on the equator permanently.

  • orbital period matches Earth’s rotation [1]
  • stays over one fixed point [1]
2
13(b)

Both use microwaves — the satellite link and the mobile phone network.

  • satellite link microwaves [1]
  • phone microwaves [1]
2
13(c)

radio waves [1]

1
Total for Question 135
14(a)

The analogue broadcast varies continuously, copying the sound’s shape; the digital broadcast switches between fixed values (on/off pulses).

  • analogue continuous [1]
  • digital fixed values / pulses [1]
2
14(b)

The digital channel: the receiver only distinguishes on from off, regenerating clean pulses and discarding the noise, so the sound stays clear even when the signal is weak and noisy.

  • digital named [1]
  • regeneration discards noise [1]
2
Total for Question 144

— End of mark scheme —