Questions
Fill in the blanks:
- mass
- nature
- shape
- size
Light of wavelength $\lambda $ from a point source falls on a small circular obstacle of diameter d. Dark and bright circular rings around a central bright spot are formed on a screen beyond the obstacle. The distance between the screen and obstacle is D. Then , the condition for the formation of rings, is
- $\sqrt { \lambda } \approx \cfrac { { d } }{ 4D } $
- $\lambda \approx \cfrac { { d }^{ 2 } }{ 4D } $
- $d\approx \cfrac { { \lambda }^{ 2 } }{ D } $
- $\lambda \approx \cfrac { D }{ 4 } $
Which of the following is incorrect?
- A thin convex lens of focal length ${f} _{1}$ is placed in contact with a thin concave lens of focal length ${f} _{2}$. The combination will act as convex lens if ${f} _{1}<{f} _{2}$
- Light on reflection at water-glass boundary will undergo a phase change of $\pi$
- Spherical aberration is minimized by achromatic lens
- If the image of distant object is formed in front of the retina then defect of vision may be myopia
The speed of the light in the medium is :-
- maximum on the axis of the beam
- minimum on the axis of the beam
- the same everywhere in the beam
- directly proportional to the intensity I
Which of the following quantities is not carried by light ?
- Angular momentum
- Linear momentum
- Energy
- None of the above
Choose the correct option about light.
- Light requires a material medium to travel from one place to another
- Light does not require a material medium to propagate
- Light has mass but it is negligible
- Light waves are longitudinal wave
During the $19th$ century, light was considered to be a stream of particles called :
- atoms
- electrons
- corpuscles
- quantas
When light falls on matter, it can produce :
- mechanical effect
- chemical effect
- heating effect
- all the above
Albert Einstein used corpuscular theory to explain :
- $E=mc^2$
- The photoelectric effect
- Quantisation of charge
- magic of light
Light is a form of _______ that we can detect with our ________ .
- energy, ears
- corpuscles, eyes
- energy, eyes
- sensation, skin
The inability of a lens to bring all the rays coming from a point object to focus at one single point is called
- Spherical aberration
- Parallex
- Optical illusion
- none
Who amongst the following used corpuscular theory to explain the nature of light?
- Max Planck
- Newton
- Young
- Einstein
By corpuscular theory of light, the phenomenon which can be explained is ____________.
- refraction
- diffraction
- interference
- polarisation
Light, like sound, cannot pass through vacuum. State whether true or false
- True
- False
Light travels in a ________ path
- rectilinear
- zig zag
- circular
- helical
- True
- False
A beam of light consists of a bundle of light rays.
- True
- False
Newton postulated his corpuscular theory of light on the basis of:
- Newton's rings.
- rectilinear propagation of light.
- colour through thin films.
- Dispersion of white light into colours.
A small plane mirror is placed at the center of the spherical screen of radius R. A beam of light is falling on the mirror. If the mirror makes n revolutions per second, the speed of light on the screen after reflection from the mirror will be:
- $4\pi nR$
- $2\pi nR$
- $nR/2\pi$
- $nR/4\pi$
Angle of incidence is equal to the angle of reflection.
- Always
- Sometimes
- Under special condition
- Never
Newton's corpuscular model of light.
- successfully explain the rectilinear propagation of light, reflection of light and refraction of light
- does not explain the phenomena of interference of light, diffraction of light and polarisation of light
- is based upon particle theory of light
- None of the above
Parallel beam is
- produced by a source at infinity
- produced by a source at finite distance
- produced by a virtual source
- None of these
Which of the following is a unit for intensity of light?
- Candle power
- Lux
- Both A & B
- None of the above
Which of the following statements applies to light?
- Light can only be described as particles.
- Light can only be described as waves.
- Light can be described as rays, waves and particles.
- Light can only be described as rays.
Which of the following statements about the behaviour of light is not correct?
- Interference patterns are evident for light behaving as rays.
- Ray properties of light are useful for understanding how images are formed by optical devices such as eyes.
- Wave properties are important for observing the behaviour of light at a fine scale.
- Both wave and particle theories of light can be related to the colour sensations produced by light.
Newton postulated his corpuscular theory of light on the basis of
- newton's rings
- rectilinear propagation of light
- colour through thin films
- dispersion of white light into colours
The size of corpuscles are ________ for different colours.
- same
- different
- either (a) or (b)
- None of these
According to corpuscular theory, the velocity of light in the denser medium is greater than that in rarer medium.
- True
- False