Physics M.C.Q (1 Marks)

In the experiment of diffraction at a single slit, if the slit width is decreased, the width of the central maximum

Red light is generally used to observe diffraction pattern from single slit. If blue light is used instead of red light, then diffraction pattern

In Fresnel diffraction, if the distance between the disc and the screen is decreased, the intensity of central bright spot will

Which statement is correct for a zone plate and a lens

Yellow light is used in single slit diffraction experiment with slit width 0.6 mm. If yellow light is replaced by X-rays then the pattern will reveal

A single slit of width 0.20 mm is illuminated with light of wavelength 500 nm. The observing screen is placed 80 cm from the slit. The width of the central bright fringe will be

Angular width (b) of central maximum of a diffraction pattern on a single slit does not depend upon

If a source of light is moving away from a stationary observer, then the frequency of light wave appears to change because of

The light of wavelength 6328 Å is incident on a slit of width 0.2 mm perpendicularly, the angular width of central maxima will be

A slit of width a is illuminated by white light. For red light (λ = 6500 Å), the first minima is obtained at θ = 30°. Then the value of a will be

Light from the constellation Virgo is observed to increase in wavelength by 0.4%. With respect to Earth the constellation is

A heavenly body is receding from earth such that the fractional change in l is 1, then its velocity is

When the wavelength of light coming from a distant star is measured it is found shifted towards red. Then the conclusion is

If a star is moving towards the earth, then the lines are shifted towards

A star is going away from the earth. An observer on the earth will see the wavelength of light coming from the star

A light source approaches the observer with velocity 0.8 c. The doppler shift for the light of wavelength 5500 Å is

In Fresnel’s biprism experiment, on increasing the prism angle, fringe width will

In Fresnel’s biprism (μ = 1.5) experiment the distance between source and biprism is 0.3 m and that between biprism and screen is 0.7m and angle of prism is 1°. The fringe width with light of wavelength 6000 Å will be

The sun is rotating about its own axis. The spectral lines emitted from the two ends of its equator, for an observer on the earth, will show

In the context of Doppler effect in light, the term ‘red shift’ signifies

The velocity of light emitted by a source S observed by an observer O, who is at rest with respect to S is c. If the observer moves towards S with velocity v, the velocity of light as observed will be

In Young’s double slit experiment, a minimum is obtained when the phase difference of super imposing waves is

A light of wavelength 5890 Å falls normally on a thin air film. The minimum thickness of the film such that the film appears dark in reflected light 

In a Young’s double slit experiment, the slit separation is 0.2 cm, the distance between the screen and slit is 1m. Wavelength of the light used is 5000 Å. The distance between two consecutive dark fringes (in mm) is

A star emits light of 5500 Å wavelength. Its appears blue to an observer on the earth, it means

The apparent wavelength of the light from a star moving away from the earth is 0.01% more than its real wavelength. Then the velocity of star is

A spectral line λ = 5000 Å in the light coming from a distant star is observed as a 5200 Å. What will be recession velocity of the star

Doppler's effect in sound in addition to relative velocity between source and observer, also depends while source and observer or both are moving. Doppler effect in light depend only on the relative velocity of source and observer. The reason of this is

Assuming that universe is expanding, if the spectrum of light coming from a star which is going away from earth is tested, then in the wavelength of light

If the shift of wavelength of light emitted by a star is towards violet, then this shows that star is

The observed wavelength of light coming from a distant galaxy is found to be increased by 0.5% as compared with that coming from a terrestrial source. The galaxy is

Two slits are separated by a distance of 0.5 mm and illuminated with light of λ = 6000 Å. If the screen is placed 2.5 m from the slits. The distance of the third bright image from the centre will be

In which of the following is the interference due to the division of wave front

In Young’s double slit experiment, the aperture screen distance is 2m. The fringe width is 1 mm. Light of 600 nm is used. If a thin plate of glass (m = 1.5) of thickness 0.06 mm is placed over one of the slits, then there will be a lateral displacement of the fringes by