Saved Bookmarks
This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A ray of light travelling in a transparent medium f refractive index `mu`, falls on a surface separating the medium from air at an angle of incidence of `45^(@)`. For which of the following value of `mu` the ray can undergo total internal reflection ?A. `mu=1.33`B. `mu = 1.40`C. `mu = 1.50`D. `mu = 1.25` |
|
Answer» Correct Answer - C |
|
| 2. |
A luminous object is placed at a distance of 30 cm. from the convex lens of focal length 20 cm. On the other side of the lens, at what distance from the lens, a convex mirror of radius of curvture 10 cm. be polaced in order to have an upright image of the object coincident with it ?A. 12 cmB. 30 cmC. 50 cmD. 60 cm |
|
Answer» Correct Answer - C |
|
| 3. |
Light enters at an angle of incidance in a tranjsparent road of refractve index `mu.` for what value of the refractive index of the material of the rod the light once entered into it will not leave it through its lateral face whatsoever be the value of angle of incidance ?A. `mugtsqrt2`B. `mu=1`C. `mu=1.1`D. `mu=1.3` |
|
Answer» Correct Answer - A |
|
| 4. |
Light travels through a glass plate of thickness t and refractive index `mu.` If c is the speed of light in vacuum, the time taken by light to travel this thickness of glass isA. `mutc`B. `(tc)/mu`C. `(1)/(mut)`D. `(mut)/c` |
|
Answer» Correct Answer - D |
|
| 5. |
The ration of resolving powers of an optical microscope for two wavelangths `lamda_(1) =4000` `Å and lamda_(2)=6000 Å is`A. `8:27`B. `9:4`C. `3:2`D. `16:81` |
|
Answer» Correct Answer - C |
|
| 6. |
Ray optics is valid, when characteristic dimensions areA. of the same order as the wavelength of lightB. much smaller than wavelength of lightC. of thr order of one millimeterD. much large than the waveiength of light |
|
Answer» Correct Answer - D |
|
| 7. |
The wavelength of light of frequenceA. `2xx10^(6)m`B. `3xx10^(6)m`C. `4xx10^(6)m`D. `5xx10^(6)m` |
|
Answer» Correct Answer - B |
|
| 8. |
Rainbows are formed byA. reflection and diffractionB. refraction and scatteringC. dispersion and total internal reflectionD. interference only |
|
Answer» Correct Answer - C |
|
| 9. |
A man is 6 ft tall In order to see his entire image, he requires a plane mirror of minimum length equal toA. `6 ft`B. `12 ft`C. `2 ft`D. `3ft` |
|
Answer» Correct Answer - B |
|
| 10. |
The angular resolution of a `10cm` diameter telescope at a wavelength `5000Å` is of the orderA. `10^(6)red`B. `10^(-2)red`C. `10^(-4)red`D. `10^(-6)red` |
|
Answer» Correct Answer - D |
|
| 11. |
A astronomical telescope has objective and eyepiece of focal lenghts 40 cm 4 cm respectively. To view an object 200 cm away from the objectiv, the lenses must be speparted by a distanceA. 46.0 cmB. 50.0 cmC. 54.0 cmD. 37.3 cm |
|
Answer» Correct Answer - C |
|
| 12. |
A concave mirrorr of focal length `f_(1)` is placed at a distance of `d` from a convex lens of focal length `f_(2)`. A beam of light coming from infinity and falling on this convex lens-concave mirrorr combination returns to infinity. The distance `d` must equal.A. `f_(1)+f_(2)`B. `-f_(1)+f_(2)`C. `2f_(1)+f_(2)`D. `-2f_(1)+f_(2)` |
|
Answer» Correct Answer - C |
|
| 13. |
A linear aperture whose width is `0.02cm` is placed immediately in front of a lens of focal length `60cm`. The aperture is illuminated normally by a parallel beam of wavelength `5xx10^-5cm`. The distance of the first dark band of the diffraction pattern from the centre of the screen isA. `0.10 cm`B. `0.25 cm`C. `0.20 cm`D. `0.15 cm` |
|
Answer» Correct Answer - D |
|
| 14. |
Which of the following pheniomeana exhibits particle nature of light ?A. interferenceB. diffractionC. polarisaationD. photoelectric effect |
|
Answer» Correct Answer - D |
|
| 15. |
In a diffraction pattern due to a single slit of width a, the firt minimum is observed at an angle `30^(@)` when light of wavelength 5000 Å is incident on the slit. The first secondary miximum is observed at an angle ofA. `sin^(-1)(2/(3))`B. `sin^(-1)(1/(2))`C. `sin^(-1)(3/(4))`D. `sin^(-1)(1/(4))` |
|
Answer» Correct Answer - C |
|
| 16. |
A transparent cube contains a small air bubble. Its apparent distance is 2 cm when seen through other facel. If the refractive index of the material of the cube is 1.5, the real length of the edge of cube must beA. `7` cmB. `7.5` cmC. `10.5` cmD. `(14)/3` cm |
|
Answer» Correct Answer - C |
|
| 17. |
Match the cprresponding entries of Coolumn 1 with Column 2. [Where m is the mangnification produced by the mirroe `{:(Column1,Column2),(A. m=-2,a."Convex mirror"),(B.m=-1/(2),b."Convave mirror"),(C.m=+2,c."Real image"),(D. m=+1/(2),d."Virtual image"):}`A. `A rarr a` and c , `B rarr a` and `d, Crarr a` and `b, D rarr c`B. `Ararra`and `d,Brarrb`andc,Crarrb`and `d,Drarrb`C. `Ararr c` and `d, Brarr b` and `d, Crarr b` and `c,Drarr a`D. `Ararrc`and `c,Brarrb`andc,Crarrb`and `d,Drarra` |
|
Answer» Correct Answer - D |
|
| 18. |
If `f(V)` and `f_(R)` are the focal lengths of a concex lens for violet and red light respectively and `F_(V)`and `F_(R)` are the focal lengths of concave lens for violet and red light respectively, then we haveA. `f_(V)gtf_(R)`and `F_(V)gtF_(R)`B. `f_(V)ltf_(R)`and `F_(V)ltF_(R)`C. `f_(V)gtf_(R)`and `F_(V)gtF_(R)`D. `f_(V)gtf_(R)`and `F_(V)ltF_(R)` |
|
Answer» Correct Answer - A |
|
| 19. |
An echlromatic combination of lenses is formed by joiningA. 2 convex lensesB. 2 convex lensesC. 1 convex, 1 concave lensD. 1 convex and 1 plane mirror |
|
Answer» Correct Answer - C |
|
| 20. |
A lens if placed between a source of light and a wall. It forms images of area` A_(1)` and `A_(2)` on the wall for its two different positions. The area of the source or light isA. `sqrt(A_(1)A_(2))`B. `(A_(1)+A_(2))/2`C. `(A_(1)-A_(2))/2`D. `(1)/A_(1)+(1)/A_(2)` |
|
Answer» Correct Answer - A |
|
| 21. |
The hypermetropia is aA. short-sight defectB. long-sight defectC. bad vision due to old ageD. None of the above |
|
Answer» Correct Answer - B |
|
| 22. |
If two mirrors are keps at `60^circ` to each other, then the number of images formed by them isA. sixB. fiveC. fourD. three |
|
Answer» Correct Answer - B |
|
| 23. |
An air bubble in a glass slab with refractive index `1.5` (near normal incidence) is `5 cm` deep when viewed from one surface and `3cm` deep when viewed from the opposite face. The thickness (in `cm)` of the slab isA. `8`B. `10`C. `12`D. `16` |
|
Answer» Correct Answer - C |
|
| 24. |
A plano-convex lens fits exactly into a plano-concave lens. Their plane surfaces are parallel to each other. If the lenses are made of different material of refractive indices `mu_(1)` and `mu_(2)` and R is the radius of curvature of the curved surface of the lenses, then focal length of the combination isA. `(R)/(2(mu_(1)+2mu_(2)))`B. `(B)/(2(mu_(1)-2mu_(2)))`C. `(R)/(2(mu_(2)-2mu_(1)))`D. `(2R)/(2(mu_(2)-2mu_(1)))` |
|
Answer» Correct Answer - C |
|
| 25. |
The diameter of human eye lens is `2 mm`. What should be the minimum separation between two points situated at `50 m` from eye, to resolve tham. Take wavelength of light `= 5000 Å`.A. `2.32` mB. `4.28` mmC. `1.25` mmD. `12.48` cm |
|
Answer» Correct Answer - C |
|
| 26. |
In a double slit experiment, the two slits are `1mm` apart and the screen is placed `1m` away. A monochromatic light of wavelength `500nm` is used. What will be the width of each slit for obtaining ten maxima of double slit within the central maxima of single-slit pattern?A. `0.2 mm`B. `0.1 mm`C. `0.5 mm`D. `0.02 mm` |
|
Answer» Correct Answer - A |
|
| 27. |
A beam of monochromatic light is refacted from vacuum into a medium of refracticve index `1.5` The wavelength of refracted light will beA. dependent on intensity of refracted lightB. sameC. smallerD. large |
|
Answer» Correct Answer - C |
|
| 28. |
A small coin is resting on the bottom of a beaker filled with a liquid. A ray of light from the coin travels up to the surface of the liquid and moves along its surface (see figure ). How fast is the light travelling in the liquid ? A. `1.8xx10^(8)M//S`B. `2.4xx10^(8)M//S`C. `3.0xx10^(8)M//S`D. `1.2xx10^(4)M//S` |
|
Answer» Correct Answer - A |
|
| 29. |
A beam of light consisting of red, green and blue colours is incident on a right angled prism. The refractive index of the material of the prism for the above red, green and blue wavelengths are 1.39, 1.44 and 1.47, respectively. A. separate the blue colour part from the red and green coloursB. separate all the three colours from one anotherC. not separtate the three colours at allD. separate the red colour part from the green and blue colours |
|
Answer» Correct Answer - D |
|
| 30. |
For a given incident ray as shown in Fig., the condition of total internal reflection of ray will be satisfied if the refractive index of the block will be. .A. `(sqrt3+1)/2`B. `(sqrt2+1)/2`C. `sqrt(2/2)`D. `sqrt(7/6)` |
|
Answer» Correct Answer - C |
|
| 31. |
A convex lens is dipped in a liquid whose refractive index is equal to the refractive of the lens. Then its focal length willA. become smallm, but non-zeroB. remain unchangedC. become zeroD. become infinite |
|
Answer» Correct Answer - D |
|
| 32. |
Focal length of a convex lens of refractive index 1.5 is 2 cm. Focal length of lens when immersed in a liquid of refractive index 1.25 will beA. `10 cm`B. `2.5 cm`C. `5 cm`D. `7.5 cm` |
|
Answer» Correct Answer - C |
|
| 33. |
When a biconvex lens of glass having refractive index `1.47` is dipped in a liquid, it acts as a plane sheet of glass. This implies that the liquid must have refractive index.A. equal to that of glassB. less than oneC. greater than that of glassD. less then that of glass |
|
Answer» Correct Answer - A |
|
| 34. |
Aplanoconvex lens is made of material of refactive index 1.6 The radius olf curvature of the curred surface is 60 cm. The facal length of the lens isA. `50 cm`B. `100 cm`C. `200 cm`D. `400 cm` |
|
Answer» Correct Answer - B |
|
| 35. |
A biconvex lens has a radius of curvature of magnitude `20cm`. Which one of the following options describes best the image formed of an object of height `2cm` place `30 cm` from the lens ?A. Virtual, upright, height= `0.5cm`B. Real, inverted, height=`4 cm`C. Real, inverted, height =`1cm`D. Virtual, upright, height=`1 cm` |
|
Answer» Correct Answer - B |
|