MDCAT Physics MCQ's Test With Answers

MDCAT Physics MCQ's Test

Sr. # Questions Answers Choice
1 Single mode step index fibre has Thick core and large cladding Thick core and shorter cladding Thin core and shorter cladding Thin core and larger cladding
2 The optical fibre is covered for protection with rubber jacket plastic jacket steel jacket copper jacket
3 An optical fibre with its protective case may be typically 6 m 6 mm 6 cm 6 nm
4 Which of the following is not an advantages of using optical fibres over copper cables? signal attenuation number of signals carried per wire cost of installation none of the above
5 Optical fibres function on the principle of reflection refraction total internal reflection total internal refraction
6 Light of wavelength 800 n m is incident on a pair of slits, forming fringes 4.0 mm apart on a screen. What is the fringe when light of 400 nm is used and the slit separation is halved? 2.0 mm 1.0 mm 4.0 mm 0.5 mm
7 Which electromagnetic wave would cause the most significant diffraction effect for an atomic lattice of spacing around 10-10m?

 microwave infrared ultraviolet X-ray
8 Polaristion is a phenomenon associated with a certain type of wave.
Which condition must be fulfilled if the wave is to be polarised?
 It must be a light wave It must be a longitudinal wave It must be a light wave It must be a transverse wave
9 Which of the following atoms cannot be detected by X-ray crystallography? carbon nitrogen hydrogen neon
10 For interference to occur, the light coming from the two slits should be monochromatic come from the same source have a constant path difference all of them
11 X-rays interact with solid crystal atoms in the crystal nuclei of atoms in the crystal electrons of atoms in the crystal
12 How are X-rays diffracted by crystals in X-rays crystallography? they bounce off the nucleus they are diffracted whey they pass from between them acting as a slit they are diffracted by the electron clouds in the atoms they hit the side the nucleus and change direction and thus are diffracted
13 X-ray crystallography can be used to get what information about the structure of a compound? the bond angles in a molecules the number of molecules per unit cell a picture of the electron density in a unit all of them
14 When the light from two lamps falls on a screen, no interference pattern can be obtained. Why is this? the light from the lamps is white the lamps emit light of different amlitudes the light from the lamps is not coherent the lamps are not point sources
15 In which situation does diffraction occur? a wave bounces back from a surface a wave meets another wave to produce a new wave a wave passes from one medium into another a wave passes through an aperture
16 Using monochromatic light, interference fringes are produced on a screen placed a distance D from a pair of slits of separation a.
The separation of the fringes is X.
a is now halved and D is increased by a factor of 4.
What is the new fringe separation?
 16 X 8 X 4 X 2 X
17 Electromagnetic waves from a source were found to be significantly diffracted when passing through gaps of the order of 10 m. What type of waves are they likely to be? gamma waves light waves microwaves radiowaves
18 A two-slit arrangement is set up to produce an interference pattern on a screen. The fringes are too close together for convenient observation. How could the distance between them be increased? by using a light of longer wavelength by increasing the width of the slits by decreasing the distance between the screen and slits the distance between the fringes is impossible
19 With a graded index fibre, the overall time difference between all the wavelengths arrived at the other end may be about 1 ns per km 10 ns per km 43 s per km 33 ns per km
20 With a step-index fibre, the overall time difference between all the wavelengths arrived at the other end may be about 43 s per km 33 s per km 1 ns per km 33 ns per km
21 The information received at the other end of a fibre can be inaccurate due to dispersion of light signal spreading of light signal both of them none of them
22 When light signal travels along fibres, the power losses are mainly due to scattering absorption both of them either of them
23 Light signals in an optical fibre eventually become dim and must be regenerated by devices called transmitters receivers photodiodes none of them
24 The absence of light in the optical fibres represents the number 0 1 2 -1
25 A pulse of light in the optical fibres represents the number 0 1 2 3
26 Which light travels faster in optical fibres? visible light ultraviolet infra-red any one of them
27 The typical wavelength of the signal which we sent in the optical fibre is 1000 nm 100 m 1.3 mn 1.3<i style="box-sizing: border-box; color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 19.8px;">μ</i><span style="box-sizing: border-box; color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 19.8px;">m</span>
28 The light source in the transmitter can be semiconductor laser LED both of them either of them
29 Which of the following converts electrical signals into light signals? optical fibre receiver reflector transmitter
30 A fibre optic communication system consists of one major component two major components three major components four major components
31 In which mode, the refractive index steps down form 1.52 to 1.48 at the boundary with the cladding? Single mode step index multimode step index multimode graded index all of them
32 Which mode can carry more than 14 TV channels or 14000 phone cells? single mod step index multimode step index multimode graded index all of them
33 Which type of fibre is used to send the signals of long distances? single mode step index fibre multimode step index fibre multimode graded index fibre all of them
34 Multi-mode step index fibre index fibre is used to send white light green light a strong monochromatic light yellow light
35 Single mode step index fibre is used to send white light green light a strong monochromatic light yellow light
36 Which optical fibre is used for shorter distances only? single mode step index fibre multi-mode step index fibre multi-mode graded index fibre all of them
37 Which of the following types of optical fibre has a core which rages in diameter from 50 to 1000μm? single mode step fibre multi-mode step index fibre multi-mode graded index fibre none of them
38 Which of the following types of optical fibre has a very thin core of about 5μm diameter and has a relatively large cladding? single mode step index fibre multi-mode step index fibre multi-mode graded index fibre none of them
39 We can divide the optical fibres on the basis of the mode by which they propagate light in two types three types four types many types
40 In which of the optical fibres, the propagation of light signal is through continuous refraction? multi-mode step index fibre multi-mode graded index fibre both of them none of them
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