The diffraction grating — Paper 1 · A Level Physics 9702

29 A diffraction grating is used to measure the wavelength of monochromatic light. The spacing of the slits in the grating is 1.15 × 10–6 m. The angle between the first order diffraction maxima is 60.0o, as shown in the diagram. grating monochromatic 60.0o light What is the wavelength of the light? A 287 nm B 498 nm C 575 nm D 996 nm

1 marks

Answer: C

This question in 9702/11 Oct/Nov 2005

27 Monochromatic light is incident on a diffraction grating and a diffraction pattern is observed. Which line of the table gives the effect of replacing the grating with one that has more lines per metre? number of orders of angle between first and diffraction visible second orders of diffraction A decreases decreases B decreases increases C increases decreases D increases increases

1 marks

Answer: B

This question in 9702/11 May/June 2006

27 The interference patterns from a diffraction grating and a double slit are compared. Using the diffraction grating, yellow light of the first order is seen at 30° to the normal to the grating. The same light produces interference fringes on a screen 1.0 m from the double slit. The slit separation is 500 times greater than the line spacing of the grating. What is the fringe separation on the screen? A 2.5 × 10–7 m B 1.0 × 10–5 m C 1.0 × 10–3 m D 1.0 × 10–1 m

1 marks

Answer: C

This question in 9702/11 Oct/Nov 2006

28 A diffraction grating has N lines per unit length and is placed at 90° to monochromatic light of wavelength λ. What is the expression for θ, the angle to the normal to the grating at which the third order diffraction peak is observed? 1 N λ 3 λ A sin θ = B sin θ = 3N λ C sin θ = 3 D sin θ = N 3 N λ

1 marks

Answer: B

This question in 9702/11 May/June 2008

25 A diffraction grating with N lines per metre is used to deflect light of various wavelengths λ. The diagram shows a relation between the deflection angles θ for different values of λ in the n th order interference pattern. sin θ 00 λ What is the gradient of the graph? N n 1 A Nn B C D n N Nn

1 marks

Answer: A

This question in 9702/11 May/June 2009

26 A parallel beam of light of wavelength 450 nm falls normally on a diffraction grating which has 300 lines / mm. What is the total number of transmitted maxima? A 7 B 8 C 14 D 15 Space for working

1 marks

Answer: D

This question in 9702/11 Oct/Nov 2009

25 A parallel beam of light of wavelength 450 nm falls normally on a diffraction grating which has 300 lines / mm. What is the total number of transmitted maxima? A 7 B 8 C 14 D 15 Space for working

1 marks

Answer: D

This question in 9702/12 Oct/Nov 2009

26 Which electromagnetic wave phenomenon is needed to explain the spectrum produced when white light falls on a diffraction grating? A coherence B interference C polarisation D refraction Space for working

1 marks

Answer: B

This question in 9702/11 May/June 2011

27 A diffraction grating with 500 lines per mm is used to observe diffraction of monochromatic light of wavelength 600 nm. The light is passed through a narrow slit and the grating is placed so that its lines are parallel to the slit. Light passes through the slit and then the grating. grating X slit light Y Z An observer views the slit through the grating at different angles, moving his head from X parallel to the grating, through Y, opposite the slit, to Z parallel to the grating on the opposite side. How many images of the slit does he see? A 3 B 4 C 6 D 7 Space for working

1 marks

Answer: D

This question in 9702/11 May/June 2011

25 Which electromagnetic wave phenomenon is needed to explain the spectrum produced when white light falls on a diffraction grating? A coherence B interference C polarisation D refraction Space for working

1 marks

Answer: B

This question in 9702/13 May/June 2011

26 A diffraction grating with 500 lines per mm is used to observe diffraction of monochromatic light of wavelength 600 nm. The light is passed through a narrow slit and the grating is placed so that its lines are parallel to the slit. Light passes through the slit and then the grating. grating X slit light Y Z An observer views the slit through the grating at different angles, moving his head from X parallel to the grating, through Y, opposite the slit, to Z parallel to the grating on the opposite side. How many images of the slit does he see? A 3 B 4 C 6 D 7 Space for working

1 marks

Answer: D

This question in 9702/13 May/June 2011

29 Monochromatic light is directed at a diffraction grating as shown. Which diagram shows all the possible directions of the light, after passing through the grating, that give maximum intensity? A B C D Space for working

1 marks

Answer: C

This question in 9702/11 Oct/Nov 2012

30 Monochromatic light of wavelength 690 nm passes through a diffraction grating with 300 lines per mm, producing a series of maxima on a screen. screen diffraction grating What is the greatest number of maxima that can be observed? A 4 B 5 C 8 D 9 Space for working

1 marks

Answer: D

This question in 9702/12 Oct/Nov 2012

29 Monochromatic light of wavelength 5.30 × 10–7 m is incident normally on a diffraction grating. The first order maximum is observed at an angle of 15.4° to the direction of the incident light. What is the angle between the first and second order diffraction maxima? A 7.6° B 15.4° C 16.7° D 32.0°

1 marks

Answer: C

This question in 9702/12 May/June 2013

27 A parallel beam of red light of wavelength 700 nm is incident normally on a diffraction grating that has 400 lines per millimetre. What is the total number of transmitted maxima? A 3 B 4 C 6 D 7 Space for working

1 marks

Answer: D

This question in 9702/13 May/June 2013

28 Light of wavelength λ passes through a diffraction grating with slit spacing d. A series of lines is observed on a screen. first order line light of α wavelength λ first order line diffraction grating screen What is the angle α between the two first order lines? sin–1  λ  sin–1  λ  2 sin–1  λ  2 sin–1  λ  A   B   C   D    2 d   d   2 d   d  Space for working

1 marks

Answer: D

This question in 9702/11 Oct/Nov 2013

28 Light of wavelength λ passes through a diffraction grating with slit spacing d. A series of lines is observed on a screen. first order line light of α wavelength λ first order line diffraction grating screen What is the angle α between the two first order lines? sin–1  λ  sin–1  λ  2 sin–1  λ  2 sin–1  λ  A   B   C   D    2 d   d   2 d   d  Space for working

1 marks

Answer: D

This question in 9702/12 Oct/Nov 2013

26 A parallel beam of white light passes through a diffraction grating. Orange light of wavelength 600 nm in the fourth order diffraction maximum coincides with blue light in the fifth order diffraction maximum. What is the wavelength of the blue light? A 450 nm B 480 nm C 500 nm D 750 nm

1 marks

Answer: B

This question in 9702/11 May/June 2014

26 Light passes through a diffraction grating ruled at 1000 lines per cm and the same wavelength of light also passes through two narrow slits 0.5 mm apart. Both situations produce intensity maxima and minima on a screen. Which statement about the separation of the maxima on the screen and the sharpness of the maxima is correct? A The diffraction grating maxima are less widely spaced and are less sharp than the two-slit maxima. B The diffraction grating maxima are less widely spaced and are sharper than the two-slit maxima. C The diffraction grating maxima are more widely spaced and are less sharp than the two-slit maxima. D The diffraction grating maxima are more widely spaced and are sharper than the two-slit maxima. Space for working

1 marks

Answer: D

This question in 9702/12 May/June 2014

30 Monochromatic light is incident on a diffraction grating and a diffraction pattern is observed. Which line of the table gives the effect of replacing the grating with one that has more lines per metre? number of orders of angle between first and diffraction visible second orders of diffraction A decreases decreases B decreases increases C increases decreases D increases increases Space for working

1 marks

Answer: B

This question in 9702/13 May/June 2014

27 A diffraction grating experiment is set up using yellow light of wavelength 600 nm. The grating has a slit separation of 2.00 µm. 2nd order yellow 1st order yellow θ2 θ1 light of wavelength grating 600 nm What is the angular separation (θ 2 – θ 1) between the first and second order maxima of the yellow light? A 17.5° B 19.4° C 36.9° D 54.3° Space for working

1 marks

Answer: B

This question in 9702/11 Oct/Nov 2014

27 A diffraction grating experiment is set up using yellow light of wavelength 600 nm. The grating has a slit separation of 2.00 µm. 2nd order yellow 1st order yellow θ2 θ1 light of wavelength grating 600 nm What is the angular separation (θ 2 – θ 1) between the first and second order maxima of the yellow light? A 17.5° B 19.4° C 36.9° D 54.3° Space for working

1 marks

Answer: B

This question in 9702/12 Oct/Nov 2014

29 White light consists of many wavelengths. The wavelength of red light R is approximately twice the wavelength of violet light V. When white light is incident normally on a diffraction grating, several spectra can be formed. Which diagram shows the possible distributions of light in the first order and the second order spectra? A B V 2nd order spectrum R 1st order 2nd order V spectrum V spectrum R R V 1st order R spectrum white white white C D R 2nd order spectrum V 1st order 2nd order R spectrum R spectrum V V R 1st order V spectrum white white white

1 marks

Answer: C

This question in 9702/12 Oct/Nov 2015

28 A diffraction grating has N lines per unit length and is placed at 90° to monochromatic light of wavelength λ. What is the expression for θ, the angle to the normal to the grating at which the third order diffraction peak is observed? 1 N λ 3 λ A sin θ = B sin θ = 3 C sin θ = 3N λ D sin θ = N 3 N λ

1 marks

Answer: C

This question in 9702/13 Oct/Nov 2015

26 Monochromatic light of wavelength 5.30 × 10–7 m is incident normally on a diffraction grating. The first order maximum is observed at an angle of 15.4° to the direction of the incident light. What is the angle between the first and second order diffraction maxima? A 7.7° B 15.4° C 16.7° D 32.1°

1 marks

Answer: C

This question in 9702/12 Feb/March 2016

26 A parallel beam of light of wavelength 450 nm is incident normally on a diffraction grating which has 300 lines / mm. What is the total number of intensity maxima observed? A 7 B 8 C 14 D 15

1 marks

Answer: D

This question in 9702/11 May/June 2016

27 A diffraction grating with N lines per metre is used to deflect light of various wavelengths λ. The graph shows a relation between the deflection angle θ and λ for different wavelengths in the n th order interference pattern. sin θ 00 λ What is the gradient of the graph? N n 1 A Nn B C D n N Nn

1 marks

Answer: A

This question in 9702/13 May/June 2016

29 A diffraction grating is used to measure the wavelength of monochromatic light. The spacing of the slits in the grating is 1.15 × 10–6 m. The angle between the first order diffraction maxima is 60.0°, as shown in the diagram. grating monochromatic 60.0° light What is the wavelength of the light? A 288 nm B 498 nm C 575 nm D 996 nm

1 marks

Answer: C

This question in 9702/11 Oct/Nov 2016

29 A diffraction grating is used to measure the wavelength of monochromatic light. The spacing of the slits in the grating is 1.15 × 10–6 m. The angle between the first order diffraction maxima is 60.0°, as shown in the diagram. grating monochromatic 60.0° light What is the wavelength of the light? A 288 nm B 498 nm C 575 nm D 996 nm

1 marks

Answer: C

This question in 9702/13 Oct/Nov 2016

28 A parallel beam of light of wavelength 600 nm is incident normally on a diffraction grating. The grating has 300 lines per millimetre. What is the total number of intensity maxima from the grating? A 1 B 3 C 11 D 13

1 marks

Answer: C

This question in 9702/11 May/June 2017

28 A parallel beam of red light of wavelength 700 nm is incident normally on a diffraction grating that has 400 lines per millimetre. What is the total number of intensity maxima from the grating? A 6 B 7 C 8 D 9

1 marks

Answer: B

This question in 9702/12 May/June 2017

27 Monochromatic light is incident on a diffraction grating and a diffraction pattern is observed. Which row shows possible effects of replacing the grating with one that has twice as many lines per millimetre? number of orders of angle between first and diffraction visible second orders of diffraction A decreases decreases B decreases increases C increases decreases D increases increases

1 marks

Answer: B

This question in 9702/13 May/June 2017

30 A diffraction grating is used to measure the wavelength of monochromatic light, as shown in the diagram. grating first order maximum monochromatic 70.0° light first order maximum The spacing of the slits in the grating is 1.00 × 10–6 m. The angle between the first order diffraction maxima is 70.0°. What is the wavelength of the light? A 287 nm B 470 nm C 574 nm D 940 nm

1 marks

Answer: C

This question in 9702/11 Oct/Nov 2017

29 A beam of light consists of two wavelengths of 436 nm and 654 nm. A diffraction grating of 5.00 × 105 lines m–1 produces a diffraction pattern in which the second order of one of these wavelengths occurs at the same angle θ as the third order of the other wavelength. overlapping orders 436 nm θ zero order 654 nm θ What is the angle θ ? A 19.1° B 25.8° C 40.8° D 78.8°

1 marks

Answer: C

This question in 9702/11 Oct/Nov 2018

30 A parallel beam of monochromatic light of wavelength λ is incident normally on a diffraction grating G. The angle between the directions of the two second-order diffracted beams at P1 and at P2 is α, as shown. P1 G light α P2 What is the spacing of the lines on the grating? 2 λ λ 2 λ λ A B C D sin α sin α sin( α / 2 ) sin(α / 2 )

1 marks

Answer: C

This question in 9702/12 Oct/Nov 2018

29 A parallel beam of white light is incident normally on a diffraction grating. The second-order and third-order spectra partially overlap. Which wavelength in the third-order spectrum appears at the same angle as the wavelength of 600 nm in the second-order spectrum? A 300 nm B 400 nm C 600 nm D 900 nm

1 marks

Answer: B

This question in 9702/13 Oct/Nov 2018

29 A diffraction grating experiment is set up using orange light of wavelength 600 nm. The grating has a slit separation of 2.00 µm. 2nd order orange 1st order orange θ2 θ1 light of wavelength grating 600 nm What is the angular separation (θ2 – θ1) between the first and second order maxima of the orange light? A 17.5° B 19.4° C 36.9° D 54.3°

1 marks

Answer: B

This question in 9702/12 Feb/March 2019

30 The interference patterns from a diffraction grating and a double slit are compared. Using the diffraction grating, yellow light of the first order is seen at 30° to the normal to the grating. The same light produces interference fringes on a screen 1.0 m from the double slit. The slit separation is 500 times greater than the line spacing of the grating. What is the fringe separation on the screen? A 2.5 × 10–7 m B 1.0 × 10–5 m C 1.0 × 10–3 m D 1.0 × 10–1 m

1 marks

Answer: C

This question in 9702/11 May/June 2019

29 Monochromatic light is directed at a diffraction grating, as shown. Which diagram could show all the possible directions of the light, after passing through the grating, that give maximum intensity? A B C D

1 marks

Answer: C

This question in 9702/12 May/June 2019

30 Monochromatic light of wavelength 690 nm passes through a diffraction grating with 300 lines per mm, producing a series of maxima (bright spots) on a screen. screen diffraction grating What is the greatest number of maxima that can be observed? A 4 B 5 C 8 D 9

1 marks

Answer: D

This question in 9702/13 May/June 2019

28 Light of wavelength 720 nm from a laser X is incident normally on a diffraction grating and a diffraction pattern is observed. Light from a laser Y is then also incident normally on the same grating. The third-order maximum due to laser Y is seen at the same place as the second-order maximum due to laser X. What is the wavelength of the light from laser Y? A 480 nm B 540 nm C 720 nm D 1080 nm

1 marks

Answer: A

This question in 9702/11 Oct/Nov 2019

29 Monochromatic light of frequency f is incident on a diffraction grating of line spacing d. The speed of light is c. Which expression can be used to determine the highest order of intensity maximum produced by the grating? d df dc c A n = cf B n = c C n = f D n = df

1 marks

Answer: B

This question in 9702/11 Oct/Nov 2019

28 An electromagnetic wave is incident normally on a diffraction grating. A second-order maximum is produced at an angle of 30° to a normal to the grating. The grating has 5000 lines per cm. What is the wavelength of the wave? A 2.5 × 10–7 m B 5.0 × 10–7 m C 1.0 × 10–6 m D 5.0 × 10–5 m

1 marks

Answer: B

This question in 9702/12 Oct/Nov 2019

30 Light of wavelength 567 nm is incident normally on a diffraction grating. The grating has 400 lines per mm. A number of diffraction maxima are observed on the far side of the grating. What is the angle between the second-order maximum and the third-order maximum? A 13.1° B 13.9° C 15.9° D 27.0°

1 marks

Answer: C

This question in 9702/13 Oct/Nov 2019

29 Light of wavelength λ is incident normally on a diffraction grating, as shown. second-order maximum light of wavelength λ ϕ diffraction second-order maximum grating The angle between the two second-order maxima is ϕ. Which expression gives the spacing of the lines on the diffraction grating? λ λ 2 λ 2 λ A ϕ B C ϕ D sin sin ( ϕ /2 ) sin sin ϕ ( / 2)

1 marks

Answer: D

This question in 9702/12 Feb/March 2020

30 A diffraction grating and a screen are used to determine the single wavelength λ of the light from a source. What is an essential feature of this experiment? A A curved screen must be used. B The diffraction angle θ must be measured for at least two interference maxima. C The light waves incident on the grating must be coherent. D The third order intensity maximum must be produced.

1 marks

Answer: C

This question in 9702/11 May/June 2020

30 Light of wavelength λ is incident normally on a diffraction grating. The angle between the second-order maximum and the normal to the grating is θ. The variation with sin θ of λ is shown on the graph. 750 λ / 10–9 m 500 250 0 0 0.2 0.4 0.6 sin θ How many lines per millimetre are on the diffraction grating? A 400 mm–1 B 625 mm–1 C 800 mm–1 D 1250 mm–1

1 marks

Answer: A

This question in 9702/12 May/June 2020

30 Light of a single wavelength from a distant point source falls normally onto a diffraction grating positioned with its lines vertical. diffraction grating light from distant point source eye of student NOT TO SCALE The plane of the diffraction grating is at right angles to the incident light. A student looks at the grating from a position near to the grating. What could the student see? A a central point source with a series of point source images on either side B a central vertical line with a series of spectra on either side C a series of fine vertical lines D a single point source

1 marks

Answer: C

This question in 9702/13 May/June 2020

29 A parallel beam of white light passes through a diffraction grating. Orange light of wavelength 600 nm in the fourth-order diffraction maximum coincides with blue light in the fifth-order diffraction maximum. What is the wavelength of the blue light? A 450 nm B 480 nm C 500 nm D 750 nm

1 marks

Answer: B

This question in 9702/11 Oct/Nov 2020

30 Light of a single frequency is incident on a diffraction grating. Seven bright spots are observed on a screen. Which change will result in an increase in the number of bright spots observed? A Increase the distance between the grating and the screen. B Increase the frequency of the incident light. C Increase the intensity of the incident light. D Increase the number of lines per metre in the grating.

1 marks

Answer: B

This question in 9702/12 Oct/Nov 2020

30 Light of wavelength 5.30  10–7 m is incident normally on a diffraction grating. The first-order maximum is observed at an angle of 15.4 to the direction of the incident light. What is the angle between the first-order and second-order diffraction maxima? A 7.7 B 15.4 C 16.7 D 32.1

1 marks

Answer: C

This question in 9702/13 Oct/Nov 2020

29 A beam of red laser light of wavelength 633 nm is incident normally on a diffraction grating with 600 lines per mm. first-order maximum light zero-order beam maximum diffraction first-order grating maximum screen 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? A 420 mm–1 B 470 mm–1 C 600 mm–1 D 850 mm–1

1 marks

Answer: D

This question in 9702/12 Feb/March 2021

29 Light of a single unknown wavelength and blue light of a single wavelength are both incident normally on a diffraction grating. Two diffraction patterns are produced, one for each wavelength of light. The third-order maximum for the blue light occurs at the same angle as the second-order maximum for the light of unknown wavelength. The wavelength of the blue light is 480 nm. What is the unknown wavelength? A 320 nm B 720 nm C 960 nm D 1440 nm

1 marks

Answer: B

This question in 9702/11 May/June 2021

30 A beam of light of a single wavelength is incident normally on a diffraction grating. The angle of diffraction  is measured for each order of diffraction n. The distance between adjacent slits in the diffraction grating is d. A graph is plotted to determine the wavelength of the light. Which graph should be plotted and how is the wavelength determined from the graph? y-axis x-axis wavelength A n d sin  gradient B n d sin  1 / gradient C sin  d / n gradient D sin  d  n 1 / gradient

1 marks

Answer: B

This question in 9702/13 May/June 2021

29 Green light is incident normally on a diffraction grating and forms a diffraction pattern on a distant screen. screen diffraction grating green light Which change, on its own, would decrease the separation of the diffraction maxima on the screen? A Increase the distance between the screen and the diffraction grating. B Replace the diffraction grating with a grating that has a smaller separation between the slits. C Replace the diffraction grating with a grating that has fewer slits per unit length. D Replace the green light with red light.

1 marks

Answer: C

This question in 9702/11 Oct/Nov 2021

30 A ray of green light is incident normally on a diffraction grating. Several bright spots are produced on a screen on the other side of the grating, as shown. bright spots ray of green light diffraction grating NOT TO SCALE screen Which pair of changes could result in bright spots at exactly the same angles as previously? A Use blue light and increase the distance between the grating and the screen. B Use blue light and increase the number of lines per unit length in the grating. C Use red light and increase the distance between the grating and the screen. D Use red light and increase the number of lines per unit length in the grating.

1 marks

Answer: B

This question in 9702/13 Oct/Nov 2021

28 Light of a single wavelength is incident normally on a diffraction grating. The resulting diffraction pattern is displayed on a screen. Which change makes the first orders of intensity maxima further apart from each other on the screen? A placing the screen closer to the diffraction grating B using a diffraction grating with less separation between adjacent slits C using a diffraction grating with more slits but keeping the same separation between adjacent slits D using light with a shorter wavelength

1 marks

Answer: B

This question in 9702/12 Feb/March 2022

30 Light of wavelength 5.4 x 10°’ mis incident normally on a diffraction grating. The separation between adjacent lines in the grating is 2.0 x 10°m. The light that emerges from the grating falls on a semicircular screen, as shown in the view from above. screen diffraction grating light, wavelength 5.4 x 107m VIEW FROM ABOVE The grating is at the centre of the semicircle, and the lines of the grating are vertical. How many bright dots are formed on the screen? A 3 B 4 C 6 D 7

1 marks

Answer: D

This question in 9702/11 May/June 2022

30 The equation d sin   = n is used to calculate the wavelength  of light in an experiment that uses a diffraction grating. The light from the diffraction grating is displayed on a screen. What do the symbols n and d represent? n d A number of slits in the grating distance between adjacent slits in the grating B number of slits in the grating distance from grating to screen C order of intensity maximum distance between adjacent slits in the grating D order of intensity maximum distance from grating to screen

1 marks

Answer: C

This question in 9702/12 May/June 2022

30 A diffraction grating has 4.00  105 lines per metre. A beam of light of wavelength 589  10–9 m is incident normally on the diffraction grating. What is the angle between the second-order maximum and the direction of the incident beam of light? A 13.6 B 27.3 C 28.1 D 56.2

1 marks

Answer: C

This question in 9702/11 Oct/Nov 2022

30 Red light of a single wavelength passes through a diffraction grating. Bright dots are formed on a screen, as shown. screen bright dot The red light is replaced with white light. Which diagram, drawn to the same scale, shows a possible pattern of bright light on the screen? A B C D

1 marks

Answer: D

This question in 9702/12 Oct/Nov 2022

29 Which property of a light wave can be determined using a diffraction grating? A amplitude B intensity C speed D wavelength

1 marks

Answer: D

This question in 9702/13 Oct/Nov 2022

29 The diagram shows a screen that is a distance L from a diffraction grating. The grating has a total number of N lines. Any two adjacent lines are a distance d apart. A beam of parallel light of wavelength J is incident normally on the grating. screen NOT TO diffraction SCALE grating beam of light first-order maxima Which quantities affect the distance between the first-order diffraction maxima on the screen? key JY = affects the distance X = does not affect the distance <x x |= NN *€ NN NJ ~*~ Q KW Nr 0 0O WwW > ~*~ << Klao

1 marks

Answer: A

This question in 9702/12 Feb/March 2023

29 Abeam of light from a laser is incident normally on a diffraction grating. light beam diffraction grating The diagram shows only the second-order maxima that are produced. The grating has a line spacing of 1.0 x 10°°m. The angle between the two second-order maxima is 110°. What is the wavelength of the light? A 4.1x10%m B 4.7x10’m C 8.2x10’m D 94x10-’m

1 marks

Answer: A

This question in 9702/11 May/June 2023

29 Green light of wavelength 550 nm is incident normally on a diffraction grating and produces a diffraction pattern on a screen placed 3.5 m from the diffraction grating. The third-order maximum on the screen is a distance of 0.75 m from the zeroth-order (central) maximum. screen NOT TO SCALE zeroth-order 3.5 m (central) maximum green light 0.75 m diffraction grating third-order maximum What is the distance between two adjacent slits in the diffraction grating? A 2.6  10–6 m B 7.7  10–6 m C 7.9  10–6 m D 1.0  10–5 m

1 marks

Answer: C

This question in 9702/12 May/June 2023

29 A parallel beam of light of wavelength 600 nm is incident normally on a diffraction grating. The distance between adjacent slits in the grating is 2.0  10–6 m. A screen is placed parallel to the grating, at a distance of 1.50 m from the grating. Third-order diffraction maxima are observed at the two ends of the screen, as shown. screen NOT TO diffraction SCALE grating third-order maxima beam of light of wavelength 600 nm 1.50 m What is the distance between the two ends of the screen? A 1.4 m B 2.7 m C 3.1 m D 6.2 m

1 marks

Answer: D

This question in 9702/13 May/June 2023

29 Light of wavelength 690 nm passes through a diffraction grating with 300 lines per mm, producing a series of bright spots (maxima) on a screen. screen diffraction grating What is the total number of bright spots that are produced? A 4 B 5 C 8 D 9

1 marks

Answer: D

This question in 9702/12 Oct/Nov 2023

29 A diffraction grating is used to measure the wavelength of light. The spacing of the slits in the grating is 1.15 10°m. The angle between the first-order diffraction maxima is 60.0°, as shown. grating light 60.0° What is the wavelength of the light? A 288nm B 498nm C 575nm D 996nm

1 marks

Answer: C

This question in 9702/13 Oct/Nov 2023

26 Light of frequency 6.7  1014 Hz in a vacuum is incident normally on a diffraction grating that contains 4.0  105 lines m–1. What is the angle between the adjacent second and third order intensity maxima? A 12 B 21 C 33 D 54

1 marks

Answer: A

This question in 9702/11 May/June 2024

26 A diffraction grating with N lines per metre is used to diffract light of various wavelengths 4. The graph shows the relation between the diffraction angle @ and 4 for different wavelengths in the n" order interference pattern. sin 6 0 0 A What is the gradient of the graph? A Nn BN Cc n 2|5 = S

1 marks

Answer: A

This question in 9702/12 May/June 2024

29 Light of wavelength 5.50 x 10°’ m from a laser is incident normally on a diffraction grating. The diffracted light is incident on a semicircular screen, as shown in the view from above. screen | | diffraction grating | light, wavelength 5.50 x 10-7m view from above A total of 9 bright dots are formed on the screen. The grating is at the centre of the semicircle. The lines of the grating are vertical. The separation between adjacent lines in the grating is d. What is a possible value of d? A 2.25x10°m B 2.80x10°m C 440x10°m D 4.95x10°%m

1 marks

Answer: A

This question in 9702/13 May/June 2024

30 Light of wavelength  is incident normally on a diffraction grating with a total number of N lines in width w. A second order maximum is observed at an angle of diffraction . What is N ? w  2w  w sin  w sin  A B C D sin  sin  2  

1 marks

Answer: C

This question in 9702/11 Oct/Nov 2024

30 The diagram shows visible light incident normally on a diffraction grating. centre of fourth order intensity maximum incident > light _. centre line diffraction grating not to scale A pattern of intensity maxima forms on the screen. A line connecting the centre of the fourth order intensity maximum with the centre of the diffraction grating forms an angle of 53° with the centre line. The grating has a line spacing of 2.7 x 10° m. What is the wavelength of the incident light? A 41x107’m B 54x10’m C 16x10°m D 2.2x10%m

1 marks

Answer: B

This question in 9702/12 Oct/Nov 2024

29 Light of wavelength 567 nm is incident normally on a diffraction grating. The grating has 400 lines per mm. A number of diffraction maxima are observed on the far side of the grating. What is the angle between the second-order maximum and the third-order maximum? A 13.1° B 13.9° C 15.9° D 27.0°

1 marks

Answer: C

This question in 9702/12 Feb/March 2025

30 Light of wavelength 680 nm is incident normally on a diffraction grating with 450 lines mm–1. What is the angle of diffraction of the second-order maximum in the diffraction pattern that is produced? A 1.8° B 3.5° C 18° D 38°

1 marks

Answer: D

This question in 9702/11 May/June 2025

29 Astudent uses a diffraction grating to determine the wavelength of visible light from a source. The diffraction grating has 300 lines per mm. The student measures the angle @ of each order n of the intensity maxima. A graph of n against sin @ is plotted. The line of best fit for the plotted points is shown and has gradient G. 0 0 sin @ Which expression represents the wavelength, in m, of the visible light in terms of G? -6 A 3x10°G B 33x10°G Cc a D

1 marks

Answer: C

This question in 9702/12 May/June 2025

28 An electromagnetic wave is incident normally on a diffraction grating. A second-order maximum is produced at an angle of 30 to the direction of the incident light. The grating has 5000 lines per cm. What is the wavelength of the wave? A 2.5  10–7 m B 5.0  10–7 m C 1.0  10–6 m D 5.0  10–5 m

1 marks

Answer: B

This question in 9702/14 May/June 2025

30 Green laser light passes through a diffraction grating and forms an interference pattern. The diffraction grating contains 400 lines per mm. The wavelength of the laser light is 550 nm. What is the highest order diffraction maximum produced by the grating? A 4 B 5 C 8 D 9

1 marks

Answer: A

This question in 9702/11 Oct/Nov 2025

29 The equation n = d sin  can be used with a diffraction grating to find the wavelength of visible light. Which quantity is not correct for use in this equation? symbol quantity A d distance from grating to screen B  wavelength of light C n order of intensity maximum D  diffraction angle of intensity maximum

1 marks

Answer: A

This question in 9702/12 Oct/Nov 2025

30 Green laser light passes through a diffraction grating and forms an interference pattern. The diffraction grating contains 400 lines per mm. The wavelength of the laser light is 550 nm. What is the highest order diffraction maximum produced by the grating? A 4 B 5 C 8 D 9

1 marks

Answer: A

This question in 9702/13 Oct/Nov 2025

30 A parallel beam of red light of wavelength 700 nm is incident normally on a diffraction grating that has 400 lines per millimetre. What is the total number of intensity maxima from the grating? A 6 B 7 C 8 D 9

1 marks

Answer: B

This question in 9702/14 Oct/Nov 2025