Lesson 4.4.2

4.4.2 Electromagnetic waves Quiz: OCR Physics, Unit 3

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 4.4.2, Electromagnetic waves: 20 multiple choice questions for the OCR Physics (H156), Unit 3: Electrons, waves and photons, written with Revision Ninja.

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The 20 questions

  1. All electromagnetic waves travel through a vacuum at a speed of:

    • 1.0 x 10^3 m/s
    • 1.5 x 10^8 m/s
    • 3.4 x 10^2 m/s
    • 3.0 x 10^8 m/s

  2. Which electromagnetic wave has the longest wavelength in the spectrum?

    • Microwaves
    • Gamma rays
    • Ultraviolet
    • Radio waves

  3. The approximate wavelength of visible light is of the order of:

    • 5 x 10^-3 m
    • 5 x 10^-7 m
    • 5 x 10^-10 m
    • 5 x 10^-1 m

  4. Gamma rays have wavelengths of the order of:

    • 10^-3 m
    • 10^3 m
    • 10^-12 m or less
    • 10^-6 m

  5. Demonstrating polarisation of electromagnetic waves shows that they are:

    • stationary
    • transverse
    • longitudinal
    • compressional

  6. A metal grille is used in demonstrations of polarisation for which radiation?

    • ultraviolet
    • visible light
    • gamma rays
    • microwaves

  7. A material has light travelling at a speed of 2.0 x 10^8 m/s. What is its refractive index?

    • 1.0
    • 0.67
    • 6.0 x 10^8
    • 1.5

  8. Light travels from air into glass of refractive index 1.5 with angle of incidence 30 degrees. What is the angle of refraction?

    • 19.5 degrees
    • 30 degrees
    • 11.5 degrees
    • 45 degrees

  9. Glass has refractive index 1.5. What is the critical angle for light travelling from glass into air?

    • 48.2 degrees
    • 19.5 degrees
    • 41.8 degrees
    • 90 degrees

  10. Total internal reflection occurs when light travels towards a medium with what property?

    • Lower refractive index
    • Zero refractive index
    • Higher refractive index
    • Equal refractive index

  11. What is the minimum possible value for the refractive index of any medium?

    • 0.5
    • 1
    • 0
    • -1

  12. The refractive index of water is 1.33. What is the speed of light in water?

    • 2.3 x 10^8 m/s
    • 3.0 x 10^8 m/s
    • 4.0 x 10^8 m/s
    • 1.3 x 10^8 m/s

  13. Light in air meets a glass block at 60 degrees to the normal and refracts to 35 degrees. What is the refractive index of the glass?

    • 1.5
    • 1.0
    • 0.66
    • 2.0

  14. What happens to the direction of a light ray entering a glass block along the normal?

    • Refracted
    • Reflected
    • Diffracted
    • Unchanged

  15. The critical angle for a material with refractive index 1.33 is closest to:

    • 41.8 degrees
    • 30.0 degrees
    • 53.1 degrees
    • 48.8 degrees

  16. How does the core refractive index in an optical fibre compare to the cladding?

    • Core is higher
    • Both are equal
    • Core is zero
    • Core is lower

  17. Light travelling in glass with refractive index 1.50 meets air at 40 degrees. What occurs?

    • Polarisation
    • Total internal reflection
    • Complete absorption
    • Refraction into air

  18. Light passes from water (n = 1.33) into glass (n = 1.5) at 30 degrees to the normal. What is the angle of refraction?

    • 22.0 degrees
    • 30.0 degrees
    • 26.3 degrees
    • 19.5 degrees

  19. Which property is unique to electromagnetic waves compared to sound waves?

    • Reflection from surfaces
    • Travel through vacuum
    • Refraction at boundaries
    • Superposition capability

  20. A microwave in air has wavelength 3.0 cm. What is its frequency?

    • 1.0 x 10^8 Hz
    • 1.0 x 10^10 Hz
    • 1.0 x 10^12 Hz
    • 9.0 x 10^8 Hz

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