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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.
| 11801. |
The focal lengths of the lenses of an astronomical telescope are 50 cm and 5 cm. The length of the telescope when the image is formed at the least distance of distinct vision is [EAMCET (Engg.) 2000] |
| A. | \[45\,cm\] |
| B. | \[55\,cm\] |
| C. | \[\frac{275}{6}\,cm\] |
| D. | \[\frac{325}{6}\,cm\] |
| Answer» E. | |
| 11802. |
The number of lenses in a terrestrial telescope is [KCET 1999; MH CET 2003] |
| A. | Two |
| B. | Three |
| C. | Four |
| D. | Six |
| Answer» C. Four | |
| 11803. |
If both the object and image are at infinite distances form a refracting telescope its magnifying power will be equal to [AMU (Engg.) 1999] |
| A. | The sum of the focal lengths of the objective and the eyepiece |
| B. | The difference of the focal lengths of the two lenses |
| C. | The ratio of the focal length of the objective and eyepiece |
| D. | The ratio of the focal length of the eyepiece and objective |
| Answer» D. The ratio of the focal length of the eyepiece and objective | |
| 11804. |
Four convergent lenses have focal lengths 100 cm, 10 cm, 4 cm and 0.3 cm. For a telescope with maximum possible magnification, we choose the lenses of focal length [KCET 1994] |
| A. | 100 cm, 0.3 cm |
| B. | 10 cm, 0.3 cm |
| C. | 10 cm, 4 cm |
| D. | 100 cm, 4 cm |
| Answer» B. 10 cm, 0.3 cm | |
| 11805. |
The astronomical telescope consists of objective and eye-piece. The focal length of the objective is [AIIMS 1998; BHU 2000] |
| A. | Equal to that of the eye-piece |
| B. | Greater than that of the eye-piece |
| C. | Shorter than that of the eye-piece |
| D. | Five times shorter than that of the eye-piece |
| Answer» C. Shorter than that of the eye-piece | |
| 11806. |
The minimum magnifying power of a telescope is M, If the focal length of its eye lens is halved, the magnifying power will become [MP PMT/PET 1998] |
| A. | M / 2 |
| B. | 2 M |
| C. | 3 M |
| D. | 4 M |
| Answer» C. 3 M | |
| 11807. |
On which of the following does the magnifying power of a telescope depends [MP PET 1992] |
| A. | The focal length of the objective only |
| B. | The diameter of aperture of the objective only |
| C. | The focal length of the objective and that of the eye piece |
| D. | The diameter of aperture of the objective and that of the eye piece |
| Answer» D. The diameter of aperture of the objective and that of the eye piece | |
| 11808. |
The aperture of the objective lens of a telescope is made large so as to [AIEEE 2003; KCET 2003] |
| A. | Increase the magnifying power of the telescope |
| B. | Increase the resolving power of the telescope |
| C. | Make image aberration less |
| D. | Focus on distant objects |
| Answer» C. Make image aberration less | |
| 11809. |
A reflecting telescope utilizes [CPMT 1983] |
| A. | A concave mirror |
| B. | A convex mirror |
| C. | A prism |
| D. | A plano-convex lens |
| Answer» B. A convex mirror | |
| 11810. |
In Gallilean telescope, the final image formed is |
| A. | Real, erect and enlarged |
| B. | Virtual, erect and enlarged |
| C. | Real, inverted and enlarged |
| D. | Virtual, inverted and enlarged |
| Answer» C. Real, inverted and enlarged | |
| 11811. |
The magnifying power of a telescope can be increased by [CPMT 1979] |
| A. | Increasing focal length of the system |
| B. | Fitting eye piece of high power |
| C. | Fitting eye piece of low power |
| D. | Increasing the distance of objects |
| Answer» C. Fitting eye piece of low power | |
| 11812. |
If Fo and Fe are the focal length of the objective and eye-piece respectively of a telescope, then its magnifying power will be CPMT 1977, 82, 97, 99, 2003; SCRA 1994; KCET 1999; Pb. PMT 2000; BHU 2001; DCE 2002; RPMT 2003; BCECE 2003, 04] |
| A. | \[{{F}_{o}}+{{F}_{e}}\] |
| B. | \[{{F}_{o}}\times {{F}_{e}}\] |
| C. | \[{{F}_{o}}/{{F}_{e}}\] |
| D. | \[\frac{1}{2}({{F}_{o}}+{{F}_{e}})\] |
| Answer» D. \[\frac{1}{2}({{F}_{o}}+{{F}_{e}})\] | |
| 11813. |
An achromatic telescope objective is to be made by combining the lenses of flint and crown glasses. This proper choice is [CPMT 1977] |
| A. | Convergent of crown and divergent of flint |
| B. | Divergent of crown and convergent of flint |
| C. | Both divergent |
| D. | Both convergent |
| Answer» B. Divergent of crown and convergent of flint | |
| 11814. |
Two points separated by a distance of 0.1 mm can just be resolved in a microscope when a light of wavelength 6000 Å is used. If the light of wavelength 4800Å is used this limit of resolution becomes [UPSEAT 2002] |
| A. | 0.08 mm |
| B. | 0.10 mm |
| C. | 0.12 mm |
| D. | 0.06 mm |
| Answer» B. 0.10 mm | |
| 11815. |
The magnifying power of a simple microscope is 6. The focal length of its lens in metres will be, if least distance of distinct vision is 25\[cm\] [MP PMT 2001] |
| A. | 0.05 |
| B. | 0.06 |
| C. | 0.25 |
| D. | 0.12 |
| Answer» B. 0.06 | |
| 11816. |
If the red light is replaced by blue light illuminating the object in a microscope the resolving power of the microscope [DCE 2001] |
| A. | Decreases |
| B. | Increases |
| C. | Gets halved |
| D. | Remains unchanged |
| Answer» C. Gets halved | |
| 11817. |
The length of the tube of a microscope is 10 cm. The focal lengths of the objective and eye lenses are 0.5 cm and 1.0 cm. The magnifying power of the microscope is about [MP PMT 2000] |
| A. | 5 |
| B. | 23 |
| C. | 166 |
| D. | 500 |
| Answer» E. | |
| 11818. |
In a compound microscope, the focal lengths of two lenses are 1.5 cm and 6.25 cm an object is placed at 2 cm form objective and the final image is formed at 25 cm from eye lens. The distance between the two lenses is [EAMCET (Med.) 2000] |
| A. | 6.00 cm |
| B. | 7.75 cm |
| C. | 9.25 cm |
| D. | 11.00 cm |
| Answer» E. | |
| 11819. |
In a compound microscope cross-wires are fixed at the point [EAMCET (Engg.) 2000] |
| A. | Where the image is formed by the objective |
| B. | Where the image is formed by the eye-piece |
| C. | Where the focal point of the objective lies |
| D. | Where the focal point of the eye-piece lies |
| Answer» B. Where the image is formed by the eye-piece | |
| 11820. |
Resolving power of a microscope depends upon [DCE 1999] |
| A. | Wavelength of light used, directly |
| B. | Wavelength of light used, inversely |
| C. | Frequency of light used |
| D. | Focal length of objective |
| Answer» C. Frequency of light used | |
| 11821. |
The objective of a compound microscope is essentially [SCRA 1998] |
| A. | A concave lens of small focal length and small aperture |
| B. | Convex lens of small focal length and large aperture |
| C. | Convex lens of large focal length and large aperture |
| D. | Convex lens of small focal length and small aperture |
| Answer» E. | |
| 11822. |
Least distance of distinct vision is 25 cm. Magnifying power of simple microscope of focal length 5 cm is [EAMCET (Engg.) 1995; Pb. PMT 1999] |
| A. | 1 / 5 |
| B. | 5 |
| C. | 1 / 6 |
| D. | 6 |
| Answer» E. | |
| 11823. |
Resolving power of a microscope depends upon [MP PET 1995] |
| A. | The focal length and aperture of the eye lens |
| B. | The focal lengths of the objective and the eye lens |
| C. | The apertures of the objective and the eye lens |
| D. | The wavelength of light illuminating the object |
| Answer» E. | |
| 11824. |
The focal lengths of the objective and the eye-piece of a compound microscope are 2.0 cm and 3.0 cm respectively. The distance between the objective and the eye-piece is 15.0 cm. The final image formed by the eye-piece is at infinity. The two lenses are thin. The distances in cm of the object and the image produced by the objective measured from the objective lens are respectively [IIT 1995] |
| A. | 2.4 and 12.0 |
| B. | 2.4 and 15.0 |
| C. | 2.3 and 12.0 |
| D. | 2.3 and 3.0 |
| Answer» B. 2.4 and 15.0 | |
| 11825. |
The magnification produced by the objective lens and the eye lens of a compound microscope are 25 and 6 respectively. The magnifying power of this microscope is [Manipal MEE 1995; DPMT 2002] |
| A. | 19 |
| B. | 31 |
| C. | 150 |
| D. | \[\sqrt{150}\] |
| Answer» D. \[\sqrt{150}\] | |
| 11826. |
When the object is self-luminous, the resolving power of a microscope is given by the expression |
| A. | \[\frac{2\mu \sin \theta }{1.22\,\lambda }\] |
| B. | \[\frac{\mu \sin \theta }{\lambda }\] |
| C. | \[\frac{2\mu \cos \theta }{1.22\ \lambda }\] |
| D. | \[\frac{2\mu }{\lambda }\] |
| Answer» B. \[\frac{\mu \sin \theta }{\lambda }\] | |
| 11827. |
The maximum magnification that can be obtained with a convex lens of focal length 2.5 cm is (the least distance of distinct vision is 25 cm) [MP PET 2003] |
| A. | 10 |
| B. | 0.1 |
| C. | 62.5 |
| D. | 11 |
| Answer» E. | |
| 11828. |
The magnifying power of a microscope with an objective of 5 mm focal length is 400. The length of its tube is 20 cm. Then the focal length of the eye-piece is [MP PMT 1991] |
| A. | 200 cm |
| B. | 160 cm |
| C. | 2.5 cm |
| D. | 0.1 cm |
| Answer» D. 0.1 cm | |
| 11829. |
Magnification of a compound microscope is 30. Focal length of eye-piece is 5 cm and the image is formed at a distance of distinct vision of 25 cm. The magnification of the objective lens is [DPMT 2005] |
| A. | 6 |
| B. | 5 |
| C. | 7.5 |
| D. | 10 |
| Answer» C. 7.5 | |
| 11830. |
A telescope has an objective lens of focal length 200 cm and an eye piece with focal length 2 cm. If this telescope is used to see a 50 meter tall building at a distance of 2 km, what is the height of the image of the building formed by the objective lens [AIIMS 2005] |
| A. | 5 cm |
| B. | 10 cm |
| C. | 1 cm |
| D. | 2 cm |
| Answer» B. 10 cm | |
| 11831. |
The diameter of objective of a telescope is 1m. Its resolving limit for the light of wave length 4538 Å, will be [Pb. PET 2003] |
| A. | \[5.54\times {{10}^{-7}}rad\] |
| B. | \[2.54\times {{10}^{-4}}rad\] |
| C. | \[6.54\times {{10}^{-7}}rad\] |
| D. | None of these |
| Answer» B. \[2.54\times {{10}^{-4}}rad\] | |
| 11832. |
In a compound microscope, if the objective produces an image Io and the eye piece produces an image Ie, then [MP PET 1990] |
| A. | Io is virtual but Ie is real |
| B. | Io is real but Ie is virtual |
| C. | Io and Ie are both real |
| D. | Io and Ie are both virtual |
| Answer» C. Io and Ie are both real | |
| 11833. |
When the length of a microscope tube increases, its magnifying power [MNR 1986] |
| A. | Decreases |
| B. | Increases |
| C. | Does not change |
| D. | May decrease or increase |
| Answer» B. Increases | |
| 11834. |
The focal length of objective and eye lens of a microscope are 4 cm and 8 cm respectively. If the least distance of distinct vision is 24 cm and object distance is 4.5 cm from the objective lens, then the magnifying power of the microscope will be |
| A. | 18 |
| B. | 32 |
| C. | 64 |
| D. | 20 |
| Answer» C. 64 | |
| 11835. |
In a compound microscope the objective of \[{{f}_{o}}\] and eyepiece of \[{{f}_{e}}\] are placed at distance L such that L equals [Kerala PMT 2004] |
| A. | \[{{f}_{o}}+{{f}_{e}}\] |
| B. | \[{{f}_{o}}-{{f}_{e}}\] |
| C. | Much greater than \[{{f}_{o}}\] or \[{{f}_{e}}\] |
| D. | Much less than \[{{f}_{o}}\] or \[{{f}_{e}}\] (e) Need not depend either value of focal lengths |
| Answer» D. Much less than \[{{f}_{o}}\] or \[{{f}_{e}}\] (e) Need not depend either value of focal lengths | |
| 11836. |
In a simple microscope, if the final image is located at infinity then its magnifying power is [MP PMT 2004] |
| A. | \[\frac{25}{f}\] |
| B. | \[\frac{D}{26}\] |
| C. | \[\frac{f}{25}\] |
| D. | \[\frac{f}{D+1}\] |
| Answer» B. \[\frac{D}{26}\] | |
| 11837. |
A simple magnifying lens is used in such a way that an image is formed at 25 cm away from the eye. In order to have 10 times magnification, the focal length of the lens should be [MP PET 1990] |
| A. | 5 cm |
| B. | 2 cm |
| C. | 25 mm |
| D. | 0.1 mm |
| Answer» D. 0.1 mm | |
| 11838. |
A Galileo telescope has an objective of focal length \[100cm\] and magnifying power 50. The distance between the two lenses in normal adjustment will be [BHU 2002; Pb. PET 2002] |
| A. | 96 cm |
| B. | 98 cm |
| C. | 102 cm |
| D. | 104 cm |
| Answer» C. 102 cm | |
| 11839. |
To increase both the resolving power and magnifying power of a telescope [Kerala PET 2002; KCET 2002] |
| A. | Both the focal length and aperture of the objective has to be increased |
| B. | The focal length of the objective has to be increased |
| C. | The aperture of the objective has to be increased |
| D. | The wavelength of light has to be decreased |
| Answer» B. The focal length of the objective has to be increased | |
| 11840. |
The resolving power of a telescope whose lens has a diameter of 1.22 m for a wavelength of 5000 Å is [Kerala PMT 2002] |
| A. | \[2\times {{10}^{5}}\] |
| B. | \[2\times {{10}^{6}}\] |
| C. | \[2\times {{10}^{2}}\] |
| D. | \[2\times {{10}^{4}}\] |
| Answer» C. \[2\times {{10}^{2}}\] | |
| 11841. |
Assertion : Although the surfaces of a goggle lens are curved, it does not have any power. Reason : In case of goggles, both the curved surfaces have equal radii of curvature. |
| A. | If both assertion and reason are true and the reason is the correct explanation of the assertion. |
| B. | If both assertion and reason are true but reason is not the correct explanation of the assertion. |
| C. | If assertion is true but reason is false. |
| D. | If the assertion and reason both are false. |
| Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 11842. |
Assertion : The illuminance of an image produced by a convex lens is greater in the middle and less towards the edges. Reason : The middle part of image is formed by undeflected rays while outer part by inclined rays. |
| A. | If both assertion and reason are true and the reason is the correct explanation of the assertion. |
| B. | If both assertion and reason are true but reason is not the correct explanation of the assertion. |
| C. | If assertion is true but reason is false. |
| D. | If the assertion and reason both are false. |
| Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 11843. |
Assertion : The resolving power of an electron microscope is higher than that of an optical microscope. Reason : The wavelength of electron is more than the wavelength of visible light. |
| A. | If both assertion and reason are true and the reason is the correct explanation of the assertion. |
| B. | If both assertion and reason are true but reason is not the correct explanation of the assertion. |
| C. | If assertion is true but reason is false. |
| D. | If the assertion and reason both are false. |
| Answer» D. If the assertion and reason both are false. | |
| 11844. |
Assertion : Critical angle of light passing from glass to air is minimum for violet colour. Reason : The wavelength of blue light is greater than the light of other colours. |
| A. | If both assertion and reason are true and the reason is the correct explanation of the assertion. |
| B. | If both assertion and reason are true but reason is not the correct explanation of the assertion. |
| C. | If assertion is true but reason is false. |
| D. | If the assertion and reason both are false. |
| Answer» D. If the assertion and reason both are false. | |
| 11845. |
Assertion : Just before setting, the sun may appear to be elliptical. This happens due to refraction. Reason : Refraction of light ray through the atmosphere may cause different magnification in mutually perpendicular directions. |
| A. | If both assertion and reason are true and the reason is the correct explanation of the assertion. |
| B. | If both assertion and reason are true but reason is not the correct explanation of the assertion. |
| C. | If assertion is true but reason is false. |
| D. | If the assertion and reason both are false. |
| Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 11846. |
A rod of glass (m = 1.5) and of square cross section is bent into the shape shown in the figure. A parallel beam of light falls on the plane flat surface A as shown in the figure. If d is the width of a side and R is the radius of circular arc then for what maximum value of \[\frac{d}{R}\] light entering the glass slab through surface A emerges from the glass through B |
| A. | 1.5 |
| B. | 0.5 |
| C. | 1.3 |
| D. | None of these |
| Answer» C. 1.3 | |
| 11847. |
A prism having an apex angle 4o and refraction index 1.5 is located in front of a vertical plane mirror as shown in figure. Through what total angle is the ray deviated after reflection from the mirror |
| A. | 176o |
| B. | 4o |
| C. | 178o |
| D. | 2o |
| Answer» D. 2o | |
| 11848. |
Absorption of X-ray is maximum in which of the following different sheets [RPMT 1995] |
| A. | Copper |
| B. | Gold |
| C. | Beryllium |
| D. | Lead |
| Answer» E. | |
| 11849. |
Compton effect is associated with [CPMT 1971] |
| A. | \[\alpha -\]rays |
| B. | \[\beta -\]rays |
| C. | X-rays |
| D. | Positive rays |
| Answer» D. Positive rays | |
| 11850. |
An X-ray has a wavelength of 0.010 Å. Its momentum is [AFMC 1980; RPMT 1995; Pb. PMT 2004] |
| A. | 2.126 \[\times \]10?23 kg-m/sec |
| B. | 6.626 \[\times \]10-22 kg-m/sec |
| C. | 3.456 \[\times \] 20?25 kg-m/sec |
| D. | 3.313 \[\times \]10?22 kg-m/sec |
| Answer» C. 3.456 \[\times \] 20?25 kg-m/sec | |