MCQOPTIONS
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MCQOPTIONS
This section includes 12583 Mcqs, each offering curated multiple-choice questions to sharpen your Joint Entrance Exam - Main (JEE Main) knowledge and support exam preparation. Choose a topic below to get started.
| 3451. |
Focal length of a convex lens will be maximum for [MP PMT 1994] |
| A. | Blue light |
| B. | Yellow light |
| C. | Green light |
| D. | Red light |
| Answer» E. | |
| 3452. |
The radius of curvature of convex surface of a thin plano-convex lens is 15 cm and refractive index of its material is 1.6. The power of the lens will be [MP PMT 1994] |
| A. | \[+1\,D\] |
| B. | \[-2\,D\] |
| C. | \[+\,3\,D\] |
| D. | \[+\,4\,D\] |
| Answer» E. | |
| 3453. |
A biconvex lens forms a real image of an object placed perpendicular to its principal axis. Suppose the radii of curvature of the lens tend to infinity. Then the image would [MP PET 1994] |
| A. | Disappear |
| B. | Remain as real image still |
| C. | Be virtual and of the same size as the object |
| D. | Suffer from aberrations |
| Answer» D. Suffer from aberrations | |
| 3454. |
A lens behaves as a converging lens in air and a diverging lens in water. The refractive index of the material is [CPMT 1991; NCERT 1979; BHU 2005] |
| A. | Equal to unity |
| B. | Equal to 1.33 |
| C. | Between unity and 1.33 |
| D. | Greater than 1.33 |
| Answer» D. Greater than 1.33 | |
| 3455. |
A double convex thin lens made of glass (refractive index \[\mu \] = 1.5) has both radii of curvature of magnitude 20 cm. Incident light rays parallel to the axis of the lens will converge at a distance L such that [MNR 1991; MP PET 1996; UPSEAT 2000; Pb PET 2004] |
| A. | L = 20 cm |
| B. | L = 10 cm |
| C. | L = 40 cm |
| D. | L = 20 / 3 cm |
| Answer» B. L = 10 cm | |
| 3456. |
An object is placed at a distance of \[f/2\] from a convex lens. The image will be [CPMT 1974, 89] |
| A. | At one of the foci, virtual and double its size |
| B. | At 3f / 2, real and inverted |
| C. | At 2f, virtual and erect |
| D. | None of these |
| Answer» B. At 3f / 2, real and inverted | |
| 3457. |
An object is placed at a distance of 20 cm from a convex lens of focal length 10 cm. The image is formed on the other side of the lens at a distance [CPMT 1971; RPET 2003] |
| A. | 20 cm |
| B. | 10 cm |
| C. | 40 cm |
| D. | 30 cm |
| Answer» B. 10 cm | |
| 3458. |
The minimum distance between an object and its real image formed by a convex lens is [CPMT 1973; JIPMER 1997] |
| A. | 1.5 \[f\] |
| B. | 2 \[f\] |
| C. | 2.5 \[f\] |
| D. | 4 \[f\] |
| Answer» E. | |
| 3459. |
A divergent lens will produce [CPMT 1984] |
| A. | Always a virtual image |
| B. | Always real image |
| C. | Sometimes real and sometimes virtual |
| D. | None of the above |
| Answer» B. Always real image | |
| 3460. |
A thin lens focal length \[{{f}_{1}}\] and its aperture has diameter d. It forms an image of intensity I. Now the central part of the aperture upto diameter \[\frac{d}{2}\] is blocked by an opaque paper. The focal length and image intensity will change to [CPMT 1989; MP PET 1997; KCET 1998] |
| A. | \[\frac{f}{2}\] and \[\frac{I}{2}\] |
| B. | \[f\] and \[\frac{I}{4}\] |
| C. | \[\frac{3f}{4}\] and \[\frac{I}{2}\] |
| D. | \[f\] and \[\frac{3I}{4}\] |
| Answer» E. | |
| 3461. |
If \[{{I}_{1}}\] and \[{{I}_{2}}\] be the size of the images respectively for the two positions of lens in the displacement method, then the size of the object is given by [CPMT 1988] |
| A. | \[{{I}_{1}}/{{I}_{2}}\] |
| B. | \[{{I}_{1}}\times {{I}_{2}}\] |
| C. | \[\sqrt{{{I}_{1}}\times {{I}_{2}}}\] |
| D. | \[\sqrt{{{I}_{1}}/{{I}_{2}}}\] |
| Answer» D. \[\sqrt{{{I}_{1}}/{{I}_{2}}}\] | |
| 3462. |
A glass lens is placed in a medium in which it is found to behave like a glass plate. Refractive index of the medium will be [CPMT 1981, 84, 85] |
| A. | Greater than the refractive index of glass |
| B. | Smaller than the refractive index of glass |
| C. | Equal to refractive index of glass |
| D. | No case will be possible from above |
| Answer» D. No case will be possible from above | |
| 3463. |
The ray diagram could be correct [CPMT 1988] |
| A. | If \[{{n}_{1}}={{n}_{2}}={{n}_{g}}\] |
| B. | If \[{{n}_{1}}={{n}_{2}}\] and \[{{n}_{1}}<{{n}_{g}}\] |
| C. | If \[{{n}_{1}}={{n}_{2}}\] and \[{{n}_{1}}>{{n}_{g}}\] |
| D. | Under no circumstances |
| Answer» D. Under no circumstances | |
| 3464. |
A glass convex lens \[({{\mu }_{g}}=1.5)\] has a focal length of \[8\,cm\] when placed in air. What would be the focal length of the lens when it is immersed in water ( \[{{\mu }_{w}}=1.33\]) [BHU 1994; MP PMT 1996] |
| A. | 2 m |
| B. | 4 cm |
| C. | 16 cm |
| D. | 32 cm |
| Answer» E. | |
| 3465. |
The dispersive power of the material of lens of focal length 20 cm is 0.08. The longitudinal chromatic aberration of the lens is [EAMCET 2005] |
| A. | 0.08 cm |
| B. | 0.08/20 cm |
| C. | 1.6 cm |
| D. | 0.16 cm |
| Answer» D. 0.16 cm | |
| 3466. |
A thin equiconvex lens is made of glass of refractive index 1.5 and its focal length is 0.2 m, if it acts as a concave lens of 0.5 m focal length when dipped in a liquid, the refractive index of the liquid is [EAMCET 2005] |
| A. | \[\frac{17}{8}\] |
| B. | \[\frac{15}{8}\] |
| C. | \[\frac{13}{8}\] |
| D. | \[\frac{9}{8}\] |
| Answer» C. \[\frac{13}{8}\] | |
| 3467. |
If the focal length of a double convex lens for red light is \[{{f}_{R}},\] its focal length for the violet light is [EAMCET 2005] |
| A. | \[{{f}_{R}}\] |
| B. | Greater than \[{{f}_{R}}\] |
| C. | Less than \[{{f}_{R}}\] |
| D. | \[2{{f}_{R}}\] |
| Answer» D. \[2{{f}_{R}}\] | |
| 3468. |
A combination of two thin lenses of the same material with focal lengths \[{{f}_{1}}\] and \[{{f}_{2}}\], arranged on a common axis minimizes chromatic aberration, if the distance between them is [EAMCET 2005] |
| A. | \[\frac{({{f}_{1}}+{{f}_{2}})}{4}\] |
| B. | \[\frac{({{f}_{1}}+{{f}_{2}})}{2}\] |
| C. | \[({{f}_{1}}+{{f}_{2}})\] |
| D. | \[2({{f}_{1}}+{{f}_{2}})\] |
| Answer» C. \[({{f}_{1}}+{{f}_{2}})\] | |
| 3469. |
The focal length of the field lens (which is an achromatic combination of two lenses) of telescope is 90 cm. The dispersive powers of the two lenses in the combination are 0.024 and 0.036. The focal lengths of two lenses are [CPMT 2005] |
| A. | 30 cm and 60 cm |
| B. | 30 cm and ? 45 cm |
| C. | 45 cm and 90 cm |
| D. | 15 cm and 45 cm |
| Answer» C. 45 cm and 90 cm | |
| 3470. |
A convex lens makes a real image 4 cm long on a screen. When the lens is shifted to a new position without disturbing the object, we again get a real image on the screen which is 16 cm tall. The length of the object must be [MP PET 1991] |
| A. | 1/4 cm |
| B. | 8 cm |
| C. | 12 cm |
| D. | 20 cm |
| Answer» C. 12 cm | |
| 3471. |
A concave lens and a convex lens have same focal length of 20 cm and both put in contact this combination is used to view an object 5 cm long kept at 20 cm from the lens combination. As compared to object the image will be [CPMT 2005] |
| A. | Magnified and inverted |
| B. | Reduced and erect |
| C. | Of the same size and erect |
| D. | Of the same size and inverted |
| Answer» D. Of the same size and inverted | |
| 3472. |
If two lenses of +5 diopters are mounted at some distance apart, the equivalent power will always be negative if the distance is [BCECE 2005] |
| A. | Greater than 40 cm |
| B. | Equal to 40 cm |
| C. | Equal to 10 cm |
| D. | Less than 10 cm |
| Answer» B. Equal to 40 cm | |
| 3473. |
The plane faces of two identical plano-convex lenses each having focal length of 40 cm are pressed against each other to form a usual convex lens. The distance from this lens, at which an object must be placed to obtain a real, inverted image with magnification one is [NCERT 1980; CPMT 1981; MP PMT 1999; UPSEAT 1999] |
| A. | 80 cm |
| B. | 40 cm |
| C. | 20 cm |
| D. | 162 cm |
| Answer» C. 20 cm | |
| 3474. |
A thin glass (refractive index 1.5) lens has optical power of \[-\,5D\] in air. It's optical power in a liquid medium with refractive index 1.6 will be [AIEEE 2005] |
| A. | 25 D |
| B. | ? 25 D |
| C. | 1 D |
| D. | None of these |
| Answer» E. | |
| 3475. |
A convex lens is in contact with concave lens. The magnitude of the ratio of their focal length is 2/3. Their equivalent focal length is 30 cm. What are their individual focal lengths [IIT-JEE (Screening) 2005] |
| A. | ? 75, 50 |
| B. | ? 10, 15 |
| C. | 75, 50 |
| D. | ? 15, 10 |
| Answer» E. | |
| 3476. |
When light rays from the sun fall on a convex lens along a direction parallel to its axis [MP PMT 2004] |
| A. | Focal length for all colours is the same |
| B. | Focal length for violet colour is the shortest |
| C. | Focal length for yellow colour is the longest |
| D. | Focal length for red colour is the shortest |
| Answer» C. Focal length for yellow colour is the longest | |
| 3477. |
Two lenses of power + 12 and ? 2 diopters are placed in contact. The combined focal length of the combination will be [Pb. PET 2004] |
| A. | 8.33 cm |
| B. | 1.66 cm |
| C. | 12.5 cm |
| D. | 10 cm |
| Answer» E. | |
| 3478. |
The focal lengths for violet, green and red light rays are \[{{f}_{V}},{{f}_{G}}\]and \[{{f}_{R}}\] respectively. Which of the following is the true relationship [BHU 2004; CBSE PMT 1997] |
| A. | \[{{f}_{R}}<{{f}_{G}}<{{f}_{V}}\] |
| B. | \[{{f}_{V}}<{{f}_{G}}<{{f}_{R}}\] |
| C. | \[{{f}_{G}}<{{f}_{R}}<{{f}_{V}}\] |
| D. | \[{{f}_{G}}<{{f}_{V}}<{{f}_{R}}\] |
| Answer» C. \[{{f}_{G}}<{{f}_{R}}<{{f}_{V}}\] | |
| 3479. |
The power of an achromatic convergent lens of two lenses is + 2D. The power of convex lens is + 5D. The ratio of dispersive power of convex and concave lens will be [Pb. PET 2003] |
| A. | 5 : 3 |
| B. | 3 : 5 |
| C. | 2 : 5 |
| D. | 5 : 2 |
| Answer» C. 2 : 5 | |
| 3480. |
The focal lengths of convex lens for red and blue light are 100 cm and 96.8 cm respectively. The dispersive power of material of lens is [Pb. PET 2003] |
| A. | 0.325 |
| B. | 0.0325 |
| C. | 0.98 |
| D. | 0.968 |
| Answer» C. 0.98 | |
| 3481. |
A convex lens of focal length 84 cm is in contact with a concave lens of focal length 12 cm. The power of combination (in diopters) is [MP PET 1991] |
| A. | 25/24 |
| B. | 25/18 |
| C. | - 50/7 |
| D. | 7.14285714285714 |
| Answer» C. - 50/7 | |
| 3482. |
Spherical aberration in a lens [UPSEAT 2004] |
| A. | Is minimum when most of the deviation is at the first surface |
| B. | Is minimum when most of the deviation is at the second surface |
| C. | Is minimum when the total deviation is equally distributed over the two surface |
| D. | Does not depend on the above consideration |
| Answer» D. Does not depend on the above consideration | |
| 3483. |
A combination of two thin convex lenses of focal length 0.3 m and 0.1 m will have minimum spherical and chromatic aberrations if the distance between them is [UPSEE 2004] |
| A. | 0.1 m |
| B. | 0.2 m |
| C. | 0.3 m |
| D. | 0.4 m |
| Answer» C. 0.3 m | |
| 3484. |
The radius of the convex surface of plano-convex lens is 20 cm and the refractive index of the material of the lens is 1.5. The focal length of the lens is [CPMT 2004] |
| A. | 30 cm |
| B. | 50 cm |
| C. | 20 cm |
| D. | 40 cm |
| Answer» E. | |
| 3485. |
A plano-convex lens is made of refractive index of 1.6. The radius of curvature of the curved surface is 60 cm. The focal length of the lens is [Pb. PET 2000] |
| A. | 400 cm |
| B. | 200 cm |
| C. | 100 cm |
| D. | 50 cm |
| Answer» D. 50 cm | |
| 3486. |
At what distance from a convex lens of focal length 30 cm, an object should be placed so that the size of the image be 1/2 of the object [J&K CET 2004] |
| A. | 30 cm |
| B. | 60 cm |
| C. | 15 cm |
| D. | 90 cm |
| Answer» E. | |
| 3487. |
A double convex lens \[({{R}_{1}}={{R}_{2}}=10\,cm)\]\[(\mu =1.5)\] having focal length equal to the focal length of a concave mirror. The radius of curvature of the concave mirror is [Orssia PMT 2004] |
| A. | 10 cm |
| B. | 20 cm |
| C. | 40 cm |
| D. | 15 cm |
| Answer» C. 40 cm | |
| 3488. |
A plano-convex lens of refractive index 1.5 and radius of curvature 30 cm is silvered at the curved surface. Now this lens has been used to form the image of an object. At what distance from this lens an object be placed in order to have a real image of the size of the object [AIEEE 2004] |
| A. | 20 cm |
| B. | 30 cm |
| C. | 60 cm |
| D. | 80 cm |
| Answer» B. 30 cm | |
| 3489. |
In order to obtain a real image of magnification 2 using a converging lens of focal length 20 cm, where should an object be placed [AFMC 2004] |
| A. | 50 cm |
| B. | 30 cm |
| C. | ? 50 cm |
| D. | ? 30 cm |
| Answer» E. | |
| 3490. |
A beam of parallel rays is brought to a focus by a plano-convex lens. A thin concave lens of the same focal length is joined to the first lens. The effect of this is [KCET 2004] |
| A. | The focal point shifts away from the lens by a small distance |
| B. | The focus remains undisturbed |
| C. | The focus shifts to infinity |
| D. | The focal point shifts towards the lens by a small distance |
| Answer» D. The focal point shifts towards the lens by a small distance | |
| 3491. |
A film projector magnifies a 100 cm2 film strip on a screen. If the linear magnification is 4, the area of magnified film on the screen is [NCERT 1980; CPMT 1977, 91; MP PET 1985, 89; RPMT 2001; BCEC 2005] |
| A. | 1600 cm2 |
| B. | 400 cm2 |
| C. | 800 cm2 |
| D. | 200 cm2 |
| Answer» B. 400 cm2 | |
| 3492. |
A magnifying glass is to be used at the fixed object distance of 1 inch. If it is to produce an erect image magnified 5 times its focal length should be [MP PMT 1990] |
| A. | 0.2 inch |
| B. | 0.8 inch |
| C. | 1.25 inch |
| D. | 5 inch |
| Answer» D. 5 inch | |
| 3493. |
In a parallel beam of white light is incident on a converging lens, the colour which is brought to focus nearest to the lens is [JIPMER 1999] |
| A. | Violet |
| B. | Red |
| C. | The mean colour |
| D. | All the colours together |
| Answer» B. Red | |
| 3494. |
When the convergent nature of a convex lens will be less as compared with air [AFMC 2003] |
| A. | In water |
| B. | In oil |
| C. | In both (a) and (b) |
| D. | None of these |
| Answer» D. None of these | |
| 3495. |
If aperture of lens is halved then image will be [AFMC 2003] |
| A. | No effect on size |
| B. | Intensity of image decreases |
| C. | Both (a) and (b) |
| D. | None of these |
| Answer» D. None of these | |
| 3496. |
The chromatic Aberration in lenses becomes due to [CPMT 2003] |
| A. | Disimilarity of main axis of rays |
| B. | Disimilarity of radii of curvature |
| C. | Variation of focal length of lenses with wavelength |
| D. | None of these |
| Answer» D. None of these | |
| 3497. |
A converging lens is used to form an image on a screen. When upper half of the lens is covered by an opaque screen [IIT-JEE 1986; SCRA 1994; MP PET 1996; MP PMT 2004; BHU 1998, 05] |
| A. | Half the image will disappear |
| B. | Complete image will be formed of same intensity |
| C. | Half image will be formed of same intensity |
| D. | Complete image will be formed of decreased intensity |
| Answer» E. | |
| 3498. |
The sun makes 0.5o angle on earth surface. Its image is made by convex lens of 50 cm focal length. The diameter of the image will be [CPMT 2003] |
| A. | 5 mm |
| B. | 4.36 mm |
| C. | 7 mm |
| D. | None of these |
| Answer» C. 7 mm | |
| 3499. |
An equiconvex lens is cut into two halves along (i) XOX¢ and (ii) YOY¢ as shown in the figure. Let f, f ¢, f ¢¢ be the focal lengths of the complete lens, of each half in case (i), and of each half in case (ii), respectively Choose the correct statement from the following [CBSE PMT 2003] |
| A. | \[{f}'=2f,\,{f}''=f\] |
| B. | \[{f}'=f,\,{f}''=f\] |
| C. | \[{f}'=2f,\,{f}''=2f\] |
| D. | \[{f}'=f,\,{f}''=2f\] |
| Answer» E. | |
| 3500. |
A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will [CBSE PMT 2003] |
| A. | Become infinite |
| B. | Become small, but non?zero |
| C. | Remain unchanged |
| D. | Become zero |
| Answer» B. Become small, but non?zero | |