SCERT Maharashtra solutions for Physics [English] 12 Standard HSC chapter 7 - Wave Optics [Latest edition]

When light travels from an optically rarer medium to an optically denser medium, the speed decreases because of change in ______ 

Light of wavelength 5000 A.U. falls on a plane reflecting surface. The frequency of reflected light is ______ 

Light follows wave nature because ______ 

Young’s double-slit experiment is carried out using green, red and blue light, one colour at a time. The fringe widths recorded are W_G, W_R, and W_B respectively then ______ 

The path difference between two waves meeting at a point is (11/4)λ. The phase difference between the two waves is ______

Which of the following cannot produce two coherent sources?

The bending of a beam of light around corners of obstacle is called ______ 

In a single slit diffraction pattern, the first minima obtained with the red light of wavelength 6600 A.U. coincides with the first maxima f some other wavelength λ then is ______  

What is the shape of the wavefront on Earth for Sunlight?

In Young’s double-slit experiment, if there is no initial phase difference between the light from the two slits, a point on the screen corresponds to the 5th minimum. What is the path difference? 

Two coherent sources whose intensity ratio is 25:1 produce interference fringes. Calculate the ratio of amplitudes of light waves coming from them.

Why two light sources must be of equal intensity to obtain a well-defined interference pattern?

What is the relation between phase difference and Optical path in terms of speed of light in a vacuum?

What should be the slit width to obtain pronounced diffraction with a single slit illuminated by the light of wavelength λ? 

What must be the ratio of the slit width to the wavelength for a single slit, to have the first diffraction minimum at 45˚? 

What are Secondary sources? State Huygens’ Principle.

A Plane Wavefront of light of wavelength 5500 A.U. is incident on two slits in a screen perpendicular to the direction of light rays. If the total separation of 10 bright fringes on a screen 2 m away is 2 cm. Find the distance between the slits.

State any four Conditions for Obtaining well–defined and Steady Interference Patterns. 

Draw a neat labelled ray diagram of the Fresnel Biprism experiment showing the region of interference. 

Answer in brief:

Explain what is the optical path length. How is it different from actual path length?

What is the difference between Fresnel and Fraunhofer diffraction? 

Compare Young’s Double Slit Interference Pattern and Single Slit Diffraction Pattern.

White light consists of wavelengths from 400 nm to 700 nm. What will be the wavelength range seen when white light is passed through a glass of refractive index 1.55?

The optical path of a ray of light of a given wavelength travelling a distance of 3 cm in flint glass having refractive index 1.6 is the same as that on travelling a distance x cm through a medium having a refractive index 1.25. Determine the value of x. 

Explain the reflection of light at a plane surface with the help of a neat ray diagram. 

Describe Young’s double-slit experiment with a neat diagram showing points of maximum and minimum intensity. 

Explain experimental setup for Fraunhofer diffraction with neat diagram. 

Answer in brief:

The distance between two consecutive bright fringes in a biprism experiment using the light of wavelength 6000 Å is 0.32 mm by how much will the distance change if light of wavelength 4800 Å is used?

A parallel beam of green light of wavelength 550 nm passes through a slit of width 0.4 mm. The intensity pattern of the transmitted light is seen on a screen that is 40 cm away. What is the distance between the two first-order minima?

In Fraunhoffer diffraction by a narrow slit, a screen is placed at a distance of 2 m from the lens to obtain the diffraction pattern. If the slit width is 0.2 mm and the first minimum is 5 mm on either side of the central maximum, find the wavelength of light.

Describe geometry of the Young’s double slit experiment with the help of a ray diagram. What is fringe width? Obtain an expression of it. Write the conditions for constructive as well as destructive interference. 

Explain Fraunhofer diffraction at a single slit with a neat ray diagram. Obtain an expression for the width of the central bright fringe. 

What is interference?

Explain constructive and destructive interference with the help of a diagram?

What are coherent sources of light?