8.4. The diffraction grating
A subsection of Physics, 9702, through 8. Superposition
Listing 10 of 66 questions
For a progressive wave, state what is meant by: the wavelength the amplitude. A beam of red laser light is incident normally on a diffraction grating. Diffraction of the light waves occurs at each slit of the grating. The light waves emerging from the slits are coherent. Explain what is meant by: 1. diffraction 2. coherent. The wavelength of the laser light is 650 nm. The angle between the third order diffraction maxima is 68°, as illustrated in . 68° third order diffraction maximum third order diffraction maximum diffraction grating laser light wavelength 650 nm (not to scale) Calculate the separation d between the centres of adjacent slits of the grating. d = m The red laser light is replaced with blue laser light. State and explain the change, if any, to the angle between the third order diffraction maxima.
9702_m20_qp_22
THEORY
2020
Paper 2, Variant 2
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A beam of red laser light of wavelength 633 nm is incident normally on a diffraction grating with 600 lines per mm. light beam diffraction grating screen first-order maximum first-order maximum zero-order maximum The beam of red light is now replaced by a beam of blue laser light of wavelength 445 nm. A replacement diffraction grating is used so that the first-order maximum of the blue light appears at the same position on the screen as the first-order maximum of the red light from the original laser. How many lines per mm are there in the replacement diffraction grating?
9702_m21_qp_12
MCQ
2021
Paper 1, Variant 2
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Explain what is meant by the diffraction of a wave. Light of wavelength 590 nm is incident normally on a diffraction grating having 750 lines per millimetre. The diffraction grating formula may be expressed in the form d sinθ = nλ. Calculate the value of d, in metres, for this grating. d = m Determine the maximum value of n for the light incident normally on the grating. maximum value of n = [T shows incident light that is not normal to the grating. Suggest why the diffraction grating formula, d sinθ = nλ, should not be used in this situation. Light of wavelengths 590 nm and 595 nm is now incident normally on the grating. Two lines are observed in the first order spectrum and two lines are observed in the second order spectrum, corresponding to the two wavelengths. State two differences between the first order spectrum and the second order spectrum. 1. 2. grating incident light diffracted light
9702_s05_qp_2
THEORY
2005
Paper 2, Variant 0
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Questions Discovered
66