The size of the pupil of the eye is adjusted by
4. blind spot
When we enter a cinema hall, we cannot see properly for a short time. This is because
1. pupil does not open
2. pupil does not close
3. adjustment of the size of pupil takes some time
4. none of these
When we go out in bright sunlight, the pupil of the eye
3. sometimes contracts and sometimes, expands
4. neither contracts nor expands
Which cells respond to colour of light?
1. Rod shaped cells
2. Coone shaped cells
3. Both types of cell
4. Neither of the two
Eye lens is a
1. double convex lens
2. double concave lens
3. plano convex lens
4. plano concave lens
The property of persistance of vision is used in
1. short sightedness
2. long sightedness
4. colour vision
Focal length of eye lens is
3. sometimes fixed and sometimes variable
4. cannot say
Variable focal length of eye lens is responsible
1. accommodation of eye
2. persistance of vision
3. colour blindness
4. least distance of distinct vision
Far point of normal human eye is
1. 25 cm
2. 25 m
3. 500 m
Near point of normal human eye is
1. 25 cm
2. 25 mm
3. 25 m
4. not fixed
when ciliary muscles are relaxed, focal length of eye lens is
3. neither maximum nor minimum
4. cannot say
Splitting of white light into seven colours on passing through a glass prism is called
Which of the colours of visible light has minimum wavelength?
Which of the colour of visible light has minimum frequency?
Which colour has maximum speed in glass?
For which colour, refractive index of glass is maximum?
Which colour suffers least deviation on passing through a prism?
Scattering of light involves
4. change in direction of light
Blue colour of sky is due to
1. scattering of light
2. reflection of light
3. refraction of light
4. diffraction of light
Twinkling of stars is due to
3. atmospheric refraction
4. none of these
Coloured band of light obtained by dispersion of white light is called
Twinkling of stars is visible when the stars are
1. any where
2. no definite situation
3. near the horizon
4. over head
The phenomena of mirage is seen due to
1. total dispersion
2. total internal interference
In an eye the focal length of the eye-lens increases when
1. ciliary muscles contracts
2. ciliary muscles expands
3. iris expands
4. iris contracts
Short sightedness is also called
Long-sightedness is also called
Eye defect at old age is called
Conevx lens is used in case of
Concave lens is used in case of
Cylindrical lens is used in case of
The intensity of scattered light varies inversely as power of wavelength of incident light where
Which of the following statements is correct about rainbow?
1. In primary rainbow, red colour is on the outside and violet colour is on the inside.
2. In primary rainbow, violet colour is on the outside and red colour os on the inside
3. Secondary rainbow is brighter than primary rainbow.
4. In secondary rainbow light wave suffers one total internal reflection before coming out
A fish looking up through the water sees the outside world contained in a circular horizon. If the refactive index of water is and the fish is 12 cm below the surface, the radius of this circle in cm is
Prism angle of a prism is . Their refractive index for red and violet colour is 1.51 and 1.52 respectively. Then dispersuve power will be
The far point of a myopic person is 80 cm in front of the eye. What is the power of the lens required to enable him to see the distant objects clearly?
1. 1.25 D
2. 1.50 D
3. 1 D
4. 1.75 D
Velocity of light in glass is and in air is . If the ray passes through glass to air, calculate the value of critical angle
Which of the following phenomena of light are involved in the formation of a rainbow?
1. Reflection, rarefaction and dispersion
2. Refraction, dispersion and total internal reflection
3. Refraction, dispersion and internal reflection
4. Dispersion, scattering and total internal reflection
A concave lens of suitable focal length is used for correcting a
1. myopic eye
2. hypermetropic eye
3. both (a) and (b)
4. neither (a) nor (b)
The broad wavelength range of visible spectrum is
4. none of these
The amplitide of scattered lightly varies with wavelength as
The intensity of scattered light varies with amplitude (a) of scattered light as
For rayleigh elastic scattering size of scatterer (x) should be
Red colour of sun at the time of sunrise and sunset is because
1. red colour is least scattered
2. blue colour is least scattered
3. red colour is scattered the most
4. all colours are equally scattered
If the refractive index of a material of equilateral prism is , then angle of minimum deviation of the prism is
Prism angle and refractive index for a prism for a and 1.414. Angle of minimum deviation will be
A piece of cloth looks red in sunlight. It is held in the blue portion of a solar spectrum, it will appear
A student sitting on the last bemch can read the letters written on the blackboard but is not able to read the letters written in his textbvook. which of the following statements is correct?
1. The near point of his eyes has receded away.
2. The near point of his eyes has come closer to him.
3. The far point of his eyes has come closer to him.
4. The far point of his eyes has receded away.
Which of the following statements is correct regarding the propagation of light of different colours of white light in air?
1. Red light moves fastest.
2. Blue light moves faster than green light.
3. All the colours of the white light move with the same speed.
4. Yellow light moves with the mean speed as that of the red and the violet light.
The refractive index of glass is 3/2. Velocity of light in glass would be
A ray of light on one face of an equilateral glass prism at and emerges from the other face at the same angle. The deviation suffered by the ray is