MCQOPTIONS
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MCQOPTIONS
This section includes 245 Mcqs, each offering curated multiple-choice questions to sharpen your UPSEE knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A Fraunhofer diffraction is produced form a light source of 580 nm. The light goes through a single slit and onto a screen a meter away. The first dark fringe is 5.0 mm form the central bright fringe. What is the slit width? |
| A. | 0.24 mm |
| B. | 0.12 mm |
| C. | 0.10 mm |
| D. | 0.52 mm |
| Answer» C. 0.10 mm | |
| 2. |
A Plano-convex lens (focal length f2 refractive index μ2 radius of curvature R) fits exactly into a plano-concave lens (focal length f1, refractive index μ1, radius of curvature R). Their plane surfaces are parallel to each other. Then, the focal length of the combination will be |
| A. | f1 – f2 |
| B. | \(\frac{{\rm{R}}}{{{{\rm{\mu }}_2} - {{\rm{\mu }}_1}}}\) |
| C. | f1 + f2 |
| D. | \(\frac{{2{{\rm{f}}_1}{{\rm{f}}_2}}}{{{{\rm{f}}_1} + {{\rm{f}}_2}}}\) |
| Answer» C. f1 + f2 | |
| 3. |
A parallel beam of light is incident on a glass item behind curtain ABCD. The emergent rays coming out from the item are as given in the following figure. Which item could be behind the curtain? |
| A. | Concave lens |
| B. | Convex lens |
| C. | Rectangular glass slab |
| D. | Prism |
| Answer» C. Rectangular glass slab | |
| 4. |
An optical fibre has a core material of refractive index of 1.55 and cladding material of refractive index of 1.50. The numerical aperture of the fibre is |
| A. | 0.05 |
| B. | 0.39 |
| C. | 3.05 |
| D. | 0.9 |
| Answer» C. 3.05 | |
| 5. |
A spherical mirror and thin spherical lens have each of focal length of + 25 cm. The mirror and the lens are likely to be |
| A. | Both concave |
| B. | Both convex |
| C. | Mirror is concave and lens is convex |
| D. | Mirror is convex and lens is concave |
| Answer» C. Mirror is concave and lens is convex | |
| 6. |
A concave mirror produces a three times magnified (enlarged) real image of an object placed at 10 cm in front of it. Which option describes the image currently? |
| A. | An inverted image is formed at a distance of 20 cm in front of the given concave mirror. |
| B. | An erect image is formed at a distance of 30 cm in front of the given concave mirror |
| C. | An inverted image is formed at a distance of 30 cm in front of the given concave mirror |
| D. | An erect image is formed at a distance of 20 cm in front of the given concave mirror |
| Answer» D. An erect image is formed at a distance of 20 cm in front of the given concave mirror | |
| 7. |
For reflection in a convex mirror the correct signs of 'u' (object distance), 'v' (image distance) and 'f' (focal length) are ___________. |
| A. | –u, +v , +f |
| B. | +u, –v, –f |
| C. | –u, +v, –f |
| D. | –u, –v, +f |
| Answer» B. +u, –v, –f | |
| 8. |
An object 5 cm in length is placed at a distance 20 cm infront of convex mirror of radius of curvature 30 cm. Find the position of image. |
| A. | 8.57 cm behind the mirror |
| B. | 8.6 cm infront of the mirror |
| C. | 6.67 cm behind the mirror |
| D. | 6.67 cm infront of the mirror |
| Answer» B. 8.6 cm infront of the mirror | |
| 9. |
A ray of light is made incident on a concave mirror, parallel to its principal axis. After reflection it will - |
| A. | pass through the centre of curvature |
| B. | move parallel to the principal axis of the mirror |
| C. | pass through the pole of the mirror |
| D. | pass through the principal focus |
| Answer» E. | |
| 10. |
Intensify of light is due to |
| A. | super position of two waves |
| B. | Doppler effect |
| C. | diffraction |
| D. | none of these |
| Answer» D. none of these | |
| 11. |
On a moving plane mirror, incident ray forms an angle of 60°, then what will be the reflected angle? |
| A. | 60° |
| B. | 90° |
| C. | 30° |
| D. | 120° |
| Answer» B. 90° | |
| 12. |
A concave mirror creates a virtual, straight, and enlarged image when the object is placed _____. |
| A. | Between F and P |
| B. | At infinity |
| C. | Between C and F |
| D. | Beyond or away from C |
| Answer» B. At infinity | |
| 13. |
If a plane wavefront is incident on a concave mirror, then the emergent wavefront will be ______________ of the mirror as its centre. |
| A. | spherical with centre of the curvature of the surface |
| B. | conical with focus |
| C. | conical with centre of the curvature of the surface |
| D. | spherical with focus |
| Answer» E. | |
| 14. |
A diffraction pattern due to a single slit has been obtained using a beam of red light. On replacing the red light with violet light, then |
| A. | diffraction bands disappear |
| B. | diffraction bands become narrower and crowd together |
| C. | no change occurs in the diffraction pattern |
| D. | diffraction bands become broader |
| Answer» C. no change occurs in the diffraction pattern | |
| 15. |
optical fibers, through bent in any manner, allows light to pass through. What is the inference which can be drawn from it? |
| A. | The concept that light travel in a straight path is wrong |
| B. | Light can flow through the optical fibers |
| C. | Light can travel through fibers because of their ductility |
| D. | Light can travel through the fibers due to multiple total internal reflections |
| Answer» E. | |
| 16. |
In case of a primary rainbow, the ray of light suffers __________________ in the water droplet. |
| A. | refraction twice and reflection once |
| B. | refraction twice and reflection twice |
| C. | reflection twice and refraction once |
| D. | reflection once and refraction once |
| Answer» B. refraction twice and reflection twice | |
| 17. |
A monochromatic light is incident at a certain angle on an equilateral triangular prism and suffers minimum deviation. If the refractive index of the material of the prism is \(\sqrt 3\), then the angle of incidence is |
| A. | 45° |
| B. | 90° |
| C. | 60° |
| D. | 30° |
| Answer» D. 30° | |
| 18. |
In an electron microscope, the resolution that can be achieved is of the order of the wavelength of electrons used. To resolve a width of 7.5 × 10-12 m, the minimum electron energy required is close to |
| A. | 500 keV |
| B. | 1 keV |
| C. | 100 keV |
| D. | 25 keV |
| Answer» E. | |
| 19. |
A virtual image larger than the object can be produced by which type of mirror? |
| A. | Convex Mirror |
| B. | Trick Mirror |
| C. | Concave Mirror |
| D. | Plane Mirror |
| Answer» D. Plane Mirror | |
| 20. |
Mirage is an illustration of |
| A. | only dispersion of light. |
| B. | only reflection of light. |
| C. | only total internal reflection of light. |
| D. | both refraction and total internal reflection of light. |
| Answer» E. | |
| 21. |
In a double slit experiment, when a thin film of thickness ‘t’ having refractive index μ is introduced in front of one of the slits, the maximum at the centre of the fringe pattern shifts by one fringe width. The value of ‘t’ is (λ is the wavelength of the light used): |
| A. | \(\frac{{2\lambda }}{{\left( {\mu - 1} \right)}}\) |
| B. | \(\frac{\lambda }{{2\left( {\mu - 1} \right)}}\) |
| C. | \(\frac{\lambda }{{\left( {\mu - 1} \right)}}\) |
| D. | \(\frac{\lambda }{{\left( {2\mu - 1} \right)}}\) |
| Answer» D. \(\frac{\lambda }{{\left( {2\mu - 1} \right)}}\) | |
| 22. |
Match the position of the image obtained with position of an object placed in front of a convex lens.Position of the imagePosition of an object place in front of a convex lensA. At infinity1. On the other side of the lens at infinityB. At focal point2. On the other side of the lens at focal pointC. At centre of curvature3. On the other side of the lens at centre of curvature |
| A. | A - 2, B - 1, C - 3 |
| B. | A - 2, B - 3, C - 1 |
| C. | A - 3, B - 1, C - 1 |
| D. | A - 3, B - 1, C - 2 |
| Answer» B. A - 2, B - 3, C - 1 | |
| 23. |
A system of three polarizers P1, P2, P3 is set up such that the pass axis of P3 is crossed with respect to that of P1. The pass axis of P2 is inclined at 60 to the pass axis of P3. When a beam of unpolarized light of intensitI0 y is incident on P1, the intensity of light transmitted by the three polarizers is I. The ratio (I0/I) equals (nearly): |
| A. | 5.33 |
| B. | 16 |
| C. | 10.67 |
| D. | 1.8 |
| Answer» D. 1.8 | |
| 24. |
_________ states that ratio of sin of angle of incidence and angle of refraction is constant |
| A. | Gravitational law |
| B. | Reflection law |
| C. | Gauss law |
| D. | Snell's law |
| Answer» E. | |
| 25. |
If an object is placed in front of a plane mirror at a distance of 10 cm from it, then the image formed will be: |
| A. | 20 cm behind the object |
| B. | 20 cm behind the mirror |
| C. | 10 cm behind the object |
| D. | 10 cm behind the mirror |
| Answer» E. | |
| 26. |
A ray parallel to the principal axis incident on a concave mirror after reflection _____________ |
| A. | retraces the path it came from |
| B. | becomes parallel to the principal axis |
| C. | passes through the focus |
| D. | deviates in such a way that when projected backwards passes through the focus |
| Answer» D. deviates in such a way that when projected backwards passes through the focus | |
| 27. |
A thin-walled cylindrical pressure vessel having a radius of 0.6 m and wall thickness of 24 mm is subjected to an internal pressure of 1000 kP. The hoop stress (MPa) developed is |
| A. | 2.5 |
| B. | 0.25 |
| C. | 25 |
| D. | 0.025 |
| E. | 22.5 |
| Answer» D. 0.025 | |
| 28. |
In a Young's double slit experiment, the slits are placed 0.320 mm apart. Light of wavelength λ = 500 nm is incident on the slits. The total number of bright fringes that are observed in the angular range -30° ≤ θ ≤ 30°is: |
| A. | 640 |
| B. | 320 |
| C. | 321 |
| D. | 641 |
| Answer» E. | |
| 29. |
Match the following optical phenomenon with the respective application : a) Total internal reflection e) Optical activity of crystals b) Interference f) Structure of crystals c) Diffraction g) Abundance of elements d) Polarisation h) Flatness of surfaces i) Optical fibres |
| A. | a-i, b-g, c-e, d-f |
| B. | a-i, b-h, c-f, d-e |
| C. | a-h, b-f, c-e, d-g |
| D. | a-f, b-h, c-i, d-e |
| Answer» C. a-h, b-f, c-e, d-g | |
| 30. |
Instrument used to observe changes in solar system is: |
| A. | Hubble telescope |
| B. | Electron telescope |
| C. | Microscope |
| D. | Both (B) and (C) |
| Answer» B. Electron telescope | |
| 31. |
A lemon kept in water in a glass tumbler appears to be larger than its actual size. It is because of |
| A. | reflection of light |
| B. | scattering of light |
| C. | refraction of light |
| D. | polarization of light |
| Answer» D. polarization of light | |
| 32. |
During dispersion of white light, the _______ light bends the least. |
| A. | green |
| B. | violet |
| C. | blue |
| D. | red |
| Answer» E. | |
| 33. |
A convex mirror forms an enlarged image of an object |
| A. | for no values of object distance |
| B. | when object distance is less than twice the focal length |
| C. | when object distance is more than twice the focal length |
| D. | for all values of object distance |
| Answer» B. when object distance is less than twice the focal length | |
| 34. |
Lightning can also cause a fire in the tree, because it contains excessive amount of |
| A. | Thermal energy |
| B. | Electrical energy |
| C. | Chemical energy |
| D. | नाभिकीय उर्जा |
| Answer» C. Chemical energy | |
| 35. |
A convex lens is made of a material having refractive index 1.2. Both the surfaces of the lens are convex. If it is dipped into water (μ = 1.33), it will behave like: |
| A. | a rectangular slab |
| B. | a prism |
| C. | a divergent lens |
| D. | a convergent lens |
| Answer» D. a convergent lens | |
| 36. |
For spherical mirrors of small apertures, the radius of curvature is found to be _______ the focal length. |
| A. | half |
| B. | same as |
| C. | thrice |
| D. | twice |
| Answer» E. | |
| 37. |
Consider the following statements about a microscope and a telescope:1. Both the eyepiece and the objective of a microscope are convex lenses.2. The focal length of the objective of a telescope is larger than the focal length of its eyepiece.3. The magnification of a telescope increases with the increase in focal length of its objective.4. The magnification of a microscope increases with the increase in focal length of its objective.Which of the statements given above are correct? |
| A. | 1 and 3 only |
| B. | 1 and 4 |
| C. | 2, 3 and 4 |
| D. | 1, 2 and 3 |
| Answer» E. | |
| 38. |
If an object is placed 10 cm in front of a convex lens of focal length 6 cm, then find the position of the image (in cm)? |
| A. | 12 |
| B. | - 15 |
| C. | 15 |
| D. | - 12 |
| Answer» D. - 12 | |
| 39. |
A concave mirror has radius of curvature of 40 cm. It is at the bottom of a glass that has water filled up to 5 cm (see figure). If a small particle is floating on the surface of water, its image as seen, from directly above the glass, is at a distance d from the surface of water. The value of d is close to:(Refractive index of water = 1.33) |
| A. | 6.7 cm |
| B. | 13.4 cm |
| C. | 8.8 cm |
| D. | 11.7 cm |
| Answer» D. 11.7 cm | |
| 40. |
Light will undergo a path difference of lamda/2 |
| A. | glass-air |
| B. | glass-water |
| C. | glass-diamond |
| D. | air-alcohol |
| Answer» D. air-alcohol | |
| 41. |
If light is allowed to pass through two polaroids 'P1' and 'P2' and 'Io' is the intensity of the polarized light after passing through 'P1', then the intensity of light (I) coming out from 'P2' will vary as ____________. |
| A. | I = Iocos2 θ |
| B. | I = Iocos θ |
| C. | I = Io2cos2 θ |
| D. | I = Io2cos θ |
| Answer» B. I = Iocos θ | |
| 42. |
As an object gets closer to the focal point of a converging lens from infinity, its image |
| A. | becomes smaller |
| B. | remains same size |
| C. | gets farther from the lens |
| D. | gets closer to the optical point of the lens |
| Answer» D. gets closer to the optical point of the lens | |
| 43. |
If the object is at infinity, then the image obtained after reflection from a concave mirror is? |
| A. | at the focus, highly enlarged, real and erect |
| B. | at the focus, highly diminished, virtual and inverted |
| C. | at the focus, highly diminished, real and inverted |
| D. | at the focus, highly enlarged, virtual and erect |
| Answer» D. at the focus, highly enlarged, virtual and erect | |
| 44. |
A symmetrical biconvex lens of focal length 'f' is cut into four identical pieces along and perpendicular to its principal axis The focal length of each of four pieces is |
| A. | 4f |
| B. | f / 4 |
| C. | 2f |
| D. | f / 2 |
| Answer» D. f / 2 | |
| 45. |
Light rays move in straight lines. But through an optical fibre, they can move in any type of zigzag path because |
| A. | the holes through the fibre are extremely fine. |
| B. | light rays are absorbed at the entry end and relieved at the exit end of the fibre. |
| C. | scattering of light occurs inside the fibre. |
| D. | successive total internal reflections occur as a ray moves through the fibre. |
| Answer» E. | |
| 46. |
A U-shaped wire is placed before a concave mirror having radius of curvature 20 cm as shown in figure. Find the total length of the image. |
| A. | 10 cm |
| B. | 40 cm |
| C. | 20 cm |
| D. | 30 cm |
| Answer» B. 40 cm | |
| 47. |
If an object is placed at 25 cm in front of a concave mirror of focal length 15 cm, then find out the image distance v. |
| A. | 38 cm |
| B. | 32.5 cm |
| C. | -32.5 cm |
| D. | -37.5 cm |
| Answer» E. | |
| 48. |
For using a convex lens as magnifying lens (magnifying glass), where should the object be placed? |
| A. | At the principal focus |
| B. | Near to the lens |
| C. | At f/2 (where f = focal length of the lens) |
| D. | Any where |
| Answer» B. Near to the lens | |
| 49. |
In an experimental arrangement of a Fresnel' biprism, monochromatic light of wavelength λ is used to produce interference fringe pattern. On introducing a thin, transparent glass sheet of refractive index 1.50 and thickness of 7 microns in the path of one of the interfering beams, the central fringe of the pattern is shifted to the position of 6th bright fringe. Then, the wavelength λ of the monochromatic light used is nearly: |
| A. | 55 nm |
| B. | 650 nm |
| C. | 618 nm |
| D. | 583 nm |
| Answer» E. | |
| 50. |
A dentist’s mirror is a? |
| A. | Convex mirror |
| B. | Cylindrical mirror |
| C. | Plane mirror |
| D. | Concave mirror |
| Answer» E. | |