Diffraction Grating

Splitting of white light in to constituent colors is called

• diffraction

• refraction

• reflection

• dispersion

Grating element is equal to

• nλ/sinθ

• nλ

• sinθ

• cosθ

With diffraction grating, angles are

• small

• greater

• zero

• close to zero

Fringes are referred to as

• minima

• maxima

• nodes

• normal points

Wavelength of an incident light when it is incident normally on a diffraction grating having 3000 lines per centimeter angular separation is 10° is

• 500 nm

• 650 nm

• 580 nm

• 600 nm

Coherent monochromatic light illuminates two narrow parallel slits and the interference pattern that results is observed on a screen some distance beyond the slits. Which change increases the separation between the dark lines of the interference pattern?

• using monochromatic light of higher frequency

• using monochromatic light of a longer wavelength

• decreasing the distance between the screen and the slits

• increasing the distance between the slits

In an interference experiment, two slits are illuminated with white light. What is seen on the screen

• The central fringe is black with black and white fringes on each side.

• The central fringe is black with colored fringes on each side.

• The central fringe is white with black and white fringes on each side.

• The central fringe is white with colored fringes on each side.

Which of the following is a longitudinal wave?

• a light wave travelling through air

• a radio wave from a broadcasting station

• a ripple on the surface of water

• a sound wave travelling through air

Continuous water waves are diffracted through a gap in a barrier in a ripple tank. Which change will cause the diffraction of the waves to increase?

• increasing the frequency of the waves

• increasing the width of the gap

• reducing the wavelength of the waves

• reducing the width of the gap

If w > λ , then

• diffraction occur

• no diffraction