Question 1 :
When light is incident on a glass block at polarizing angle<br/>a) reflected ray is plane polarized<br/>b) reflected and refracted rays are perpendicular<br/>c) reflected and refracted rays are partially polarized<br/>d) refracted ray is partially polarised<br/>
Question 2 :
The ability of an optical instruments to show the images of two adjacent point objects as separate is called :
Question 3 :
When the light is incident at the polarizing angle on transparent medium, then the completely polarized light is
Question 4 :
Among the Fresnel zones the operative zones contributing intensity are :<br/>
Question 6 :
Pile of plates can be used to produce completely polarised light due to :<br/>
Question 8 :
To increase both the resolving power and magnifying power of a telescope<br/>
Question 9 :
Unpolarized light falls on two polarizing sheets so oriented that no light is transmitted. If a third polarizing sheet is placed between them; not parallel to either of the above two sheets in question:<br/>
Question 10 :
An electron microscope is superior to an optical microscope in terms of:<br>
Question 12 :
A light ray is incident on a glass slab it is partially reflected and partially transmitted. Then the reflected ray is<br>
Question 13 :
The critical angle for total internal reflection for a substance is $45^{\circ}$. The polarizing angle for this substance is ($\tan 54^{\circ}44'=\sqrt{2}$) :<br/>
Question 15 :
In an astronomical microscope, the focal length of the objective is made :<br/>
Question 17 :
The angle of incidence at which reflected light is totally polarised for reflection from air to glass (refractive index $n$) is :<br>
Question 18 :
If the red light is replaced by blue light illuminating the object in a microscope the resolving power of the microscope
Question 19 :
When unpolarized light beam is incident from air onto glass $(n=1.5)$ at the polarizing angle,
Question 21 :
If plane-polarized light is sent through two polarizers, the first at $ 45^{\circ} $ to the original plane of polarization and the second at $ 90^{\circ} $ to the original plane of polarization, what fraction of the original polarized intensity passes through the last polarizer?
Question 22 :
At a time, the image of sun formed due to reflection at air-water interface, is found to be highly polarized. If refractive index of water is $\mu =\dfrac{4}{3}$, then the angle of the sun above the horizon is ?
Question 23 :
The angle between the pass axis of polarizer and analyzer is $45^{\circ}$. The percentage of polarised light passing through analyzer is:
Question 24 :
In the Fresnel bi-prism experiment, the refractive index for the bi-prism is $\mu=3/2$ and fringe width obtained is $0.4mm$. If the whole apparatus is immersed as such in water then the fringe width will become(refractive index of water is $4/3$).
Question 26 :
What is effect on fresnel biprism experiment, when the white light is used ?<br>
Question 27 :
When a plane polarised light is passed through an analyser and analyser is rotated through $90^{o}$, the intensity of the emerging light
Question 29 :
In Fresnel bi-prism experiment, the distance between the source and the screen $1m$ and that between the source and bi-prism is $10cm$. The wavelength of light used is $6000A^o$. The fringe width obtained is $0.03cm$ and the refracting angle of bi-prism is $1$. The refractive index of the material of bi-prism is
Question 30 :
The resolving power of an electron microscope operated at 16 kV is R. The resolving power of the electron microscope when operated at 4 kV is<br>
Question 31 :
At what angle of incidence will the light reflected from glass $( \mu \, = \, 1.5)$ be completely polarised
Question 32 :
A ray of light travelling in impure water is incident on a glass plate immersed in it. When the angle of incidence is $51^o$, the reflected ray is totally plane polarized. Given that refractive index of impure water if $1.4$. The refractive index of glass should be __________.$(\tan 51^o=1.235)$.
Question 33 :
From Brewster's law of polarisation, it follows that the angle of polarisation depends upon
Question 34 :
The critical angle of a certain medium is <span class="MathJax_Preview"></span><span class="MathJax"><span class="math"><span><span><span class="mrow"><span class="msubsup"><span><span><span class="mi">sin</span><span></span></span><span><span class="texatom"><span class="mrow"><span class="mo">−</span><span class="mn">1</span></span></span><span></span></span></span></span><span class="mspace"></span><span class="mrow"><span class="mo"><span>(</span></span><span class="mstyle"><span class="mrow"><span class="mfrac"><span><span><span class="mn">3</span><span></span></span><span><span class="mn">5</span><span></span></span><span><span></span><span></span></span></span></span></span></span><span class="mo"><span>)</span></span></span></span><span></span></span></span><span></span></span><span class="MJX_Assistive_MathML">sin−1(35)</span></span> The polarizing angle of the medium is:
Question 35 :
A person wishes to distinguish between two pillars located at a distance of 11 km. What should be the minimum distance between these pillars (resolving power of normal human eye is 1')?<br>
Question 36 :
Two point white dots are 1 mm apart on a black paper. They are viewed by eye of pupil of diameter 3 mm. Approximately what is the maximum distance up to which these dots can be resolved by the eye.<br>
Question 37 : <p>Polarizing angle for water is $53^o4'$. If light is incident at this angle on the surface of water and reflected the angle of refraction is:</p>
Question 38 :
The limit of resolution of an optical instrument is the smallest angle that two points on an object have to subtend at the eye so that they are.
Question 39 :
Light from a mercury arc lamp is passed through a filter that blocks everything except for one spectrum line in the green region of the spectrum.<br/>It then falls on two slits separated by 0.6 mm. In the resulting interference pattern on a screen 2.5 mm away, adjacent bright fringes are separated by 2.27 nm. The wavelength is:<br/>
Question 40 :
With the help of a telescope that has an objective of diameter $200cm$, it is proved that light of wavelengths of the order of $6400\mathring { A } $ coming from a star can be easily resolved. Then the limit of resolution is
Question 41 :
Wavelength of light used in an optical instrument are $\lambda_1 = 4000 A^o and \lambda_2 = 5000 A^0$, then ratio of their respective resolving powers (corresponding to $\lambda_1 \ and \ \lambda_2$) is
Question 42 :
Two polarising plates have polarising directions parallel, so as to transmit maximum intensity of light. Through what angle must either plate be turned, if the intensities of the transmitted beam is to drop by half.
Question 43 :
Unpolarized red light is incident on the surface of a lake at incident angle $\theta_R$. An observer seeing the light reflected from the water surface through a polarizer notices that on rotating the polarizer, the intensity of light drops to zero at a certain orientation. The red light is replaced by unpolarized blue light. The observer sees the same effect with reflected blue light at incident angle $\theta_s$. Then :
Question 44 :
An aperture of size a is illuminated by a parallel beam of light of wavelength $\lambda$. The distance at which ray optics has a good approximation is
Question 45 :
The correct relation between $S, \theta, L $ and $C$ for an optically active solution is:
Question 47 :
A biprism experiment was performed by using red light of wavelength $ 6500\mathring{A} $ and blue light of wavelength $ 5200\mathring{A}$. the value of n for which $ (n+1)^{th} $ blue bright band coincides with $ n^{th} $ red band is
Question 49 :
In a fresnel's bi-prism experiment , the refracting angles of the prism were 2.5$^o$ and the refracting index of the glass was 1.5 . With the single slit 10 cm from the bi-prism ,fringes were formed on a screen 1 m from the single slit . The fringe width is 0.1375 mm . The wavelength of light is
Question 50 : <p>What is the minimum angular separation between two stars if a telescope is used to observe them with an objective of circular aperture $20\ cm$? The wavelength light used is $5900\;\mathop {\text{A}}\limits^{\text{0}} .$</p>
Question 51 :
When a thin wedge-shaped film is illuminated by a parallel beam of light of wavelength 6000 A$^{\circ}$, 7 fringes are observed in a certain region of the film. What will be the number of fringes observed in the same region of a film if light of wavelength 4200 A$^{\circ}$ is used? <br>
Question 52 :
ASSERTION: Resolving power of telescope is more if the diameter of the objective lens is more.<br/>REASON:Objective lens of large diameter collects more light.<br/>
Question 53 :
An astronomical telescope has on objective and an eyepiece of focal lengths $10 cm$ and $1 cm$ respectively. Find its tube length in normal adjustment.
Question 54 :
doctor prescribes spectacles to a patient with a combination of a convex lens of focal length 40 em, and concave lens of focal length 25 em then the power of spectacles will be.
Question 55 :
$V_{o}$ and $V_{E}$ represented the velocities $\mu_{0}$ and $\mu_{E}$ the refractive indices of ordinary and extraordinary rays for a doubly refracting crystal. Then
Question 56 :
Unpolarized light is incident on a plane glass surface. The angle of incidence so that reflected and refracted rays are perpendicular to each other, then:
Question 57 :
In a diffraction pattern by a wire, on increasing diameter of wire, fringe width
Question 58 :
If prism angle $\alpha =1^o, \mu =1.54$, distance between screen and prism $(D)=0.7m$, distance between prism and source $a=0.3m, \lambda =180\pi nm$, then in Fresnal biprism find the value of $\beta$ (fringe width)
Question 59 :
The numerical aperture of objective of a microscope is $0.12$. The limit of resolution, when light of wavelength $6000\mathring { A } $ is used to view an object is:
Question 60 :
A spectral line $\lambda=5000\overset{o}{A}$ in the light coming from a distant star is observed as a $5200\overset{o}{A}$. What will be recession velocity of the star
Question 61 :
The limit of resolution of 100 cm telescope for $\lambda=5000 \mathring {A}$ is approximately equal to
Question 62 :
Two wavelengths $\lambda _{1}$ and $\lambda _{2}$ are used in bi-prism experiment. If $\lambda _{1}$ is 430 nm, the value of the wavelength $\lambda_2$ such that its fourth order bright fringe falls over the sixth order bright fringe of $\lambda _{1}$ would be<br>
Question 63 :
The limit of resolution of microscope, if the numerical aperture of microscope is 0.12, and the wavelength of light used is 600 nm, is <br/>
Question 64 :
A Polaroid is placed at $45^0$ to an incoming light of intensity $I_0$. Now the intensity of light passing through Polaroid after polarization would be
Question 65 :
Two point white dots are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 mm. Approximately, what is the maximum distance at which these dots can be resolved by the eye? [Take wave length of light =500 nm]
Question 66 :
A linearly polarized light is incident at Brewster angle on the surface of a dielectric medium .If the incident beam is polarized parallel to the plane of incidence , then which one of the following statement is correct ?
Question 67 :
Choose the Correct answer from alternative given.<br>When the angle of incidence is 60$^{o}$ on the surface of a glass slab, it is found that the reflected ray is completely polarized. The velocity of light in glass is
Question 68 :
If Fresnel's biprism experiment as held in water in spite of air, then what will be the effect on fringe width<br>
Question 69 :
For what distance is ray optics a good approximation when the aperture is 4 mm wide and the wavelength is 500 nm?
Question 70 :
The distance between the slit and the bi-prism and that of between bi-prism and screen each is $0.4m$. The obtuse angle of bi-prism is $179^0$ and refractive index is $1.5$. If the fringe width is $1.8\times 10^{-4}m$ then the distance between imaginary sources will be
Question 71 :
Interference fringes are formed by a biprism of angle $1^o$ and refractive index $1.5$ . The slit is fixed at a distance of $10cm$ from the biprism and is illuminated by the light of wavelength $600 nm$. Calculate the fringe width at a distance of $1 m$ from the biprism in mm.
Question 72 :
Light from sodium lamp is made to pass through two polaroids placed one after the other in the path of light. Taking the intensity of the incident light as 100%, the intensity of the out coming light that can be varied in the range:
Question 73 :
Calculate the limit of resolution of a telescope objective having a diameter of 200 cm, if it has to detect light of wavelength 500 nm coming from a star ; -
Question 74 :
In a biprism experiment, the micrometer readings for the zero order and $10^{th}$ order fringe are $1.25 mm$ and $2.37 mm$ respectively, when light of $600 nm$ is used. If the wavelength is changed to $750 nm$, What will be the respective position of zero and $10^{th}$ order fringes ?
Question 75 :
In a Fresnel's biprism experiment using sodium light, fringe widths of $195$ <br> $\mu$m are obtained at a distance of $1.0\ m$ from the slit . A convex lens is then put between the observer and prism so as to give the image of the source at a distance of $1.0\ m$ from the slit . The distance apart of the images is found to be $0.7\ cm$, the lens being $30\ cm$ from the slit . Calculate the wavelength of the sodium light used.
Question 76 :
A beam of microwaves whose wavelength is 0.052 m is coming towards a rectangular aperture of width 0.35 m . Resultant diffraction pattern is observing on a wall at 8.0 m distance from aperture . The distance between first and second order outer fringes will be :
Question 77 :
In a Fresnel's bi-prism experiment, the fringe of width $0.05mm$ is observed on a screen at a distance of $1.5m$ from the source . When a convex lens is placed between the source and the screen, for two positions of the lens image of interfering sources are produced on the screen. The separation between the two images being $0.04$ and $0.01mm$, respectively. The wavelength of light used is
Question 78 :
A paper, with two marks having separation d, is held normal to the line of sight of an observer at a distance of 50m. The diameter of the eye-lens of the observer is 2 mm. Which of the following is the least value of d, so that the marks can be seen as separate? (The mean wavelength of visible light may be taken as 5000 $A^o$)
Question 79 :
An astronomical telescope, consists of two thin lenses set $36 cm$ a part and has a magnifying power $8$. Calculate the focal length of the lenses.
Question 80 :
Assuming human pupil to have a radius of 0.25 cm and a comfortable viewing distance of 25cm, the minimum separation between two objects that human eye can resolve at 500 nm wavelength is :
Question 81 :
A light wave is incident normally on a glass slab of refractive index $1.5$. If $4\%$ of light gets reflected and the amplitude of the electric field of the incident light is $30\ V/m$,then the amplitude of the electric field for the wave propogating in the glass medium will be:
Question 82 :
The diameter of the objective lens of microscope makes an angle $'\beta\ '$ at the focus of the microscope. Further, the medium between the object and the lens is an oil of refractive index 'n'. Then the resolving power of the microscope.
Question 83 :
Fresnel diffraction is produced due to light rays falling on a small obstacle. The intensity of light at a point on a screen beyond an obstacle depends on <span>:<br/></span>
Question 84 :
In an electron microscope the accelerating voltage is increased from 20 kV to 80 kV, the resolving power of the microscope will change from R to<br/>
Question 85 :
Angular width of central maximum in the Fraunhoffer diffraction pattern of a slit is measured. The slit is illuminated by light of wavelength $6000\mathring { A } $. When the slit is illuminated by light of another wavelength, then the angular width decreases by $30$%. The same decrease in angular width of central maximum is obtained when the original apparatus is immersed in a liquid. The refractive index of the liquid will be
Question 86 :
Assume that light of wavelength $600 nm$ is coming from a star. The limit of resolution of telescope whose objective has a diameter of $2m$ is :
Question 87 :
A ray of light is incident from a denser to a rarer medium. The critical angle for total internal reflection is $\theta_{iC}$ and the Brewster's angle of incidence is $\theta_{iB}$, such that $sin\theta_{iC}/sin\theta_{iB}=n=1.28$. The relative refractive index of the two media is :
Question 88 :
When an object is viewed with a light of wavelength $6000\mathring{A}$ under a microscope, its resolving power is $10^4$. The resolving power of the microscope when the same object is viewed with a light of wavelength $4000\mathring{A}$, is:
Question 89 :
<span>A ray of unpolarized light is incident on a glass plate at the polarizing angle ${\theta _P}$ .Then </span>
Question 90 :
If the polarizing angle of a piece of glass for green light is 54.74$^{o}$, then the angle of minimum deviation for an equilateral prism made of same glass is :<br/>[GIVEN, tan 54.74$^{o}$ = 1.414]
