The Physics of Light

Q. In the double slit experiment if a glass slab is introduced in the path of light the slits to the screen-

Ans. The central maxima will be at the same location and the fringe width will decrease

Q. Which of the following statement about normal dispersion is correct?

Ans. The index of refraction increases as the wavelength decreases-

Q. Anomalous dispersion of a transparent substance like quartz can show in-

Ans. Infrared range

Q. Nicol prism is made from-

Ans. Calcite

Q. The wavelength of a moving particle is inversely proportional to-

Ans. Momentum

Q. According to Huygen’s principle of secondary wavelets each particle at a wavefront-

Ans. Behaves as a new light source

Q. A Nichol prism is based on the action of-

Ans. Double refraction

Q. If white light is incident in a diffraction grating the light that will be deviated least from the central maximum is-

Ans. Violet

Q. In general continuous emission spectra is obtained from-

Ans. Liquids and solids only

Q. The refractive index of Canada balsam is-

Ans. 1.5

Q. The amplitude of the light wave at a distance x is A. At a point distant 3x from the source the amplitude would be-

Ans. A/3

Q. The transverse nature of electromagnetic radiation is conclusively established by the principle of-

Ans. Polarization

Q. Two slits are spaced 0.3 mm apart and are placed 50 cm from a screen. Then the distance between the second and the third dark lines when the slits are illuminated with light of 600 mm wavelength is-

Ans. 2 mm

Q. A shift of an interference pattern with blue light is observed when a colorless thin paralleled film is introduced in the path of the refracted beam from one half of the biprism. If the colorless film is replaced by a red film of the same thickness and refractive index the shift-

Ans. Increases

Q. When the blue glass is heated the color of glow will be-

Ans. Red

Q. Infrared photography is based which of the following principle?

Ans. The peak of maximum radiation varies with the temperature emitting IR

Q. The intensity of bright and dark is almost constant in-

Ans. An interference pattern only

Q. When plane-polarized light passes through an optically active material the plane of polarization is rotated through an angle that depends on-

Ans. Material

Q. There are several reasons why a lens may not produce a sharp image of an object point. Which one of the following is the valid reason?

Ans. The lens is diverging

Q. Which color light has the longest wavelength?

Ans. Red

Q. The maximum distance from which the mm markings on a meter scale can be seen by the eye of aperture 2 mm is near-

Ans. 4 meters

Q. Hologram-

Ans. Three-dimensional view of an object

Q. The refractive index for diamond is-

Ans. 2.45

Q. The black lines on the spectrogram of white light from the sun are called-

Ans. Fraunhofer lines

Applied Physics – Laser & Atomic Structure

Q. The phenomenon associated with periscope is-

Ans. Total internal reflection

Q. Carbon dioxide is filled in a discharge tube. Which of the following spectrum will be obtained from the discharge tube?

Ans. Band specture

Q. In Young’s experiment of interference, a torch is a used in place of the sodium lamp. Which of the following statement is correct?

Ans. Colored fringes will be produced

Q. During interference of light-

Ans. Energy is gained

Q. In the whole of the Young,s experiment is kept in water which of the following changes will take place?

Ans. The fringe width will decreases

Q. The refractive index of glass is at least for-

Ans. Red light

Q. In Young’s experiment, one slit is covered with a blue filter and the other slit with yellow. The interference pattern will look-

Ans. Green

Q. For interference to take place the two source of light-

Ans. Must have the same frequency

Q. A continuous spectrum is emitted by-

Ans. While hot solider

Q. Refraction index will be the least case of-

Ans. Dry-air

Q. Camera lenses are often coated to-

Ans. Reduce unwanted reflection

Q. The resolving power of a lens is-

Ans. Its ability to separate the images of two points that are close together