
Explain how the second-order maximum arises in terms of path difference.

Important Questions on Superposition of Waves
Monochromatic light is incident normally on a diffraction grating having lines per centimetre. The angular separation of the zeroth- and first-order maxima is found to be . If , calculate the angle for the second-order maximum.

Monochromatic light is incident normally on a diffraction grating having lines per centimetre. The angular separation of the zeroth- and first-order maxima is found to be . If , calculate the angle for the second-order maximum.
(b) Repeat the calculation of for , and so on. Determine how many maxima can be seen. Explain your answer.

Consider the equation . State and explain how the interference pattern would change when:
(a) The wavelength of the incident light is increased for the same grating

Consider the equation . State and explain how the interference pattern would change when:
(b) The grating is changed for one with more lines per for the same incident light.

A student is trying to make an accurate measurement of the wavelength of green light from a mercury lamp. The wavelength $\lambda$ of this light is . Using a double-slit of separation , the student can see clear bright fringes on a screen at a distance of from the slits. The student can measure their overall width to within
Using a ruler. The student then tries an alternative experiment using a diffraction grating with lines . The angle between the two second-order maxima can be measured to within .
(a) Determine the width of the fringes that the student can measure in the first experiment.

A student is trying to make an accurate measurement of the wavelength of green light from a mercury lamp. The wavelength $\lambda$ of this light is . Using a double-slit of separation , the student can see clear bright fringes on a screen at a distance of from the slits. The student can measure their overall width to within
Using a ruler. The student then tries an alternative experiment using a diffraction grating with lines . The angle between the two second-order maxima can be measured to within .
(b) Determine the angle of the second-order maximum that the student can measure in the second experiment.

A student is trying to make an accurate measurement of the wavelength of green light from a mercury lamp. The wavelength $\lambda$ of this light is . Using a double-slit of separation , the student can see clear bright fringes on a screen at a distance of from the slits. The student can measure their overall width to within
Using a ruler. The student then tries an alternative experiment using a diffraction grating with lines . The angle between the two second-order maxima can be measured to within .
(c) Based on your answers to parts and , suggest which experiment you think will give the more accurate value of .

White light is incident normally on a diffraction grating with a slit-separation of . The visible spectrum has wavelengths between and .
(a) Calculate the angle between the red and violet ends of the first-order spectrum.
