Optics One Liner Questions & Answers


Questions Answers
1 The visible range of solar radiation is – 400-700 nm
2 The wavelength extension of visible light is – Between 390-780 nm
3 The wavelength of the visible spectrum is in the range – 3900 Å – 7600 Å
4 The human eye is most sensitive to visible light of the wavelength – 5500 Å
5 The eye is most sensitive to colours between – Yellow and green
6 The nature of radiation of light is – Like both of wave and particle
7 Light appears to travel in a straight line because – The wavelength of light is very small
8 The speed of light in a vacuum is near – 3 × 108metre/sec
9 Velocity of light is maximum in – Vacuum
10 The speed of light will be minimum while passing through – Glass
11 The time taken to reach the Sunlight up to the surface of earth is approximately – 8.5 minutes
12 Who has the highest velocity? Light
13 What does not change when light travels from one medium to another? Frequency
14 When light waves pass from air to glass the variable affected are – Wavelength and velocity
15 When a ray of light travels from a denser medium to a rarer medium then – It speeds up and bends away from the normal
16 The formation of glittering colours in the thin foam of soap is the result of the following phenomenon – Total refection and interference
17 Total internal reflection can take place when light travels from – Diamond to glass
18 A cut diamond shines brilliantly due to – Total internal reflection
19 What is the reason behind the extraordinary shining of the diamond cuts in a proper way? Because it has a fixed deviation for
20 Optical fibre works on the principle of – Total internal reflection
21 In fiber-optic communication, the signal travels in the form of – Lightwave
22 ‘Endoscope’ used by the doctors for examining the inside of patient’s stomach, works on the principle of – Total internal refection of light
23 The reason of the mirage is – Total internal refection of light
24 The technique to integrate and mark the image of a three-dimensional object is – Holography
25 Generating images on a screen by focusing an electronic beam on phosphorus-coated screen is called – Roster Scan
26 ‘Raman effect’ deals with the light rays passing through – Only fluids
27 For reproducing sound, a CD (Compact Disc) audio player uses a – Laser beam
28 When a CD (compact disc used in audio and video systems) is seen in sunlight, rainbow-like colours is seen. This can be explained on the basis of the phenomenon of – Reflection and diffraction
29 Television signals cannot be received beyond a certain distance because – The surface of the earth is curved
30 The technique used to transmit audio signals in television broadcasts is – Frequency Modulation
31 In the human eye, light rays get transformed into neural impulses at – Retina
32 The image formed on Retina is – Smaller than object but inverted
33 Which type of image of an object is formed by eye lens of the retina? Inverted and Real
34 The principal reason why it is better to have two eyes than one is that – It enhances distance and depth perception in us.
35 Direct viewing of sun during total solar eclipse causes irreversible damage to the eyes. The retinal burn is caused by which component of the sun rays? Ultraviolet light
36 The colour of the star is an indication of its – Temperature
37 Difusion of light in the atmosphere takes place due to – Dust particles
38 The colour of light is determined by its – Wavelength
39 Which colors have the longest wavelength? Red
40 The light with the shortest wavelength is – Violet
41 The sun is visible to us a few minutes before the actual sunrise because of – Refraction of light
42 The sun and the moon appear elliptical near the horizon because of – Refraction
43 Red light is used in traffic signals because – It has the longest wavelength
44 Red light signal is used as a danger signal because – Red light is scattered least
45 The Sky appears blue due to – The blue color is scattered most
46 An astronaut sees the colour of the sky as – Black
47 When we see the sky from a plane in high altitude, then it seems – Black
48 The sea seems blue due to –
Refection of sky and scattering of light by the drops of water
49 The (Green) Grass appears green to us because – It refects green colour light to our eyes
50 In driving a car which type of mirror would you like to use for observing traffic at your back? Convex mirror
51 The image formed by an astronomical telescope is – Virtual and magnified
52 The number of images of an object placed between two parallel mirrors is – Infinite
53 When a mirror is rotated by an angle θ, the reflected ray will rotate by –
54 Light is made of seven colors. What is the method of separating the colors? The colours can be separated by a prism
55 The correct order of colours in a rainbow is – Blue, green, yellow
56 The terminal color bands of the rainbow are – Violet and Red
57 In which direction the rainbow is seen at 12 noon? It cannot be seen
58 An air bubble in water will act like a – Concave lens
59 The radius of curvature of the plane mirror is – Infinity
60 Reading glasses are made from which type of lense? Convex mirror
61 A myopic eye can be corrected by using a – Concave lens
62 The focus in the eye is done by – Change in the convexity of the lens
63 The change of focal length of an eye lens is caused by action of the – Ciliary muscles
64 The least distance of distinct vision is (cm.) – 25
65 The power of a lens is measured in – Dioptre
66 If the lens power of glass is +2 dioptre, its focal length will be – 50 cm
67 The colour of an opaque object is due to the colour it – Reflects
68 Colour in a colour television is produced by a combination of three basic colours, they are – Red, green and blue
69 When beams of red, blue, and green lights fall on the same spot, the color of the light becomes – White
70 The number of colors contained in the sunlight is – 7