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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.
| 3351. |
If \[\hat{i}\] denotes a unit vector along incident light ray, \[\hat{r}\] a unit vector along refracted ray into a medium of refractive index \[\mu \] and \[\hat{n}\] unit vector normal to boundary of medium directed towards incident medium, then law of refraction is [EAMCET (Engg.) 1995] |
| A. | \[\hat{i}\,.\,\hat{n}=\mu (\hat{r}\,.\,\hat{n})\] |
| B. | \[\hat{i}\times \hat{n}=\mu (\hat{n}\times \hat{r})\] |
| C. | \[\hat{i}\times \hat{n}=\mu (\hat{r}\times \hat{n})\] |
| D. | \[\mu (\hat{i}\times \hat{n})=\hat{r}\times \hat{n}\] |
| Answer» D. \[\mu (\hat{i}\times \hat{n})=\hat{r}\times \hat{n}\] | |
| 3352. |
On heating a liquid, the refractive index generally [KCET 1994] |
| A. | Decreases |
| B. | Increases or decreases depending on the rate of heating |
| C. | Does not change |
| D. | Increases |
| Answer» B. Increases or decreases depending on the rate of heating | |
| 3353. |
A man standing in a swimming pool looks at a stone lying at the bottom. The depth of the swimming pool is h. At what distance from the surface of water is the image of the stone formed (Line of vision is normal; Refractive index of water is n) [KCET 1994] |
| A. | h / n |
| B. | n / h |
| C. | h |
| D. | hn |
| Answer» B. n / h | |
| 3354. |
A mark at the bottom of a liquid appears to rise by 0.1 m. The depth of the liquid is 1 m. The refractive index of the liquid is [CPMT 1999] |
| A. | 1.33 |
| B. | \[\frac{9}{10}\] |
| C. | \[\frac{10}{9}\] |
| D. | 1.5v |
| Answer» D. 1.5v | |
| 3355. |
When light is refracted from air into glass [IIT 1980; CBSE PMT 1992; MP PET 1999; MP PMT 1999; RPMT 1997, 2000, 03; MH CET 2004] |
| A. | Its wavelength and frequency both increase |
| B. | Its wavelength increases but frequency remains unchanged |
| C. | Its wavelength decreases but frequency remains unchanged |
| D. | Its wavelength and frequency both decrease |
| Answer» D. Its wavelength and frequency both decrease | |
| 3356. |
The distance travelled by light in glass (refractive index =1.5) in a nanosecond will be [MP PET 1999] |
| A. | 45 cm |
| B. | 40 cm |
| C. | 30 cm |
| D. | 20 cm |
| Answer» E. | |
| 3357. |
The time taken by sunlight to cross a 5 mm thick glass plate \[(\mu =3/2\]) is [MP PMT/PET 1998; BHU 2005] |
| A. | 0.25\[\times \]10?10 \[s\] |
| B. | \[0.167\times {{10}^{-7}}\]\[s\] |
| C. | \[2.5\times {{10}^{-10}}\]\[s\] |
| D. | \[1.0\times {{10}^{-10}}\]\[s\] |
| Answer» B. \[0.167\times {{10}^{-7}}\]\[s\] | |
| 3358. |
When light travels from one medium to the other of which the refractive index is different, then which of the following will change [MP PMT 1986; AMU 2001; BVP 2003] |
| A. | Frequency, wavelength and velocity |
| B. | Frequency and wavelength |
| C. | Frequency and velocity |
| D. | Wavelength and velocity |
| Answer» E. | |
| 3359. |
Which of the following is a correct relation [MP PET 1997] |
| A. | \[_{a}{{\mu }_{r}}={{\,}_{a}}{{\mu }_{w}}\times \,{{\,}_{r}}{{\mu }_{\omega }}\] |
| B. | \[_{a}{{\mu }_{r}}\times {{\,}_{r}}{{\mu }_{w}}={{\,}_{w}}{{\mu }_{a}}\] |
| C. | \[_{a}{{\mu }_{r}}\times {{\,}_{r}}{{\mu }_{a}}=0\] |
| D. | \[_{a}{{\mu }_{r}}/{{\,}_{w}}{{\mu }_{r}}={{\,}_{a}}{{\mu }_{w}}\] |
| Answer» E. | |
| 3360. |
Which of the following is not a correct statement [MP PET 1997] |
| A. | The wavelength of red light is greater than the wavelength of green light |
| B. | The wavelength of blue light is smaller than the wavelength of orange light |
| C. | The frequency of green light is greater than the frequency of blue ligh |
| D. | The frequency of violet light is greater than the frequency of blue light |
| Answer» D. The frequency of violet light is greater than the frequency of blue light | |
| 3361. |
Light of wavelength is \[7200\,{AA}\] in air. It has a wavelength in glass (\[\mu =1.5\]) equal to [DCE 1999] |
| A. | \[7200\,\,{AA}\] |
| B. | \[4800\,\,{AA}\] |
| C. | \[10800\,\,{AA}\] |
| D. | \[7201.5\,\,{AA}\] |
| Answer» C. \[10800\,\,{AA}\] | |
| 3362. |
Monochromatic light of frequency \[5\times {{10}^{14}}\]Hz travelling in vacuum enters a medium of refractive index 1.5. Its wavelength in the medium is [MP PET/ PMT 1995; Pb. PET 2003] |
| A. | \[4000\,\,{AA}\] |
| B. | \[5000\,\,{AA}\] |
| C. | \[6000\,\,{AA}\] |
| D. | \[5500\,\,{AA}\] |
| Answer» B. \[5000\,\,{AA}\] | |
| 3363. |
Refractive index of glass is \[\frac{3}{2}\] and refractive index of water is \[\frac{4}{3}\]. If the speed of light in glass is \[2.00\times {{10}^{8}}\] m/s, the speed in water will be [MP PMT 1994; RPMT 1997] |
| A. | \[2.67\times {{10}^{8}}\] m/s |
| B. | \[2.25\times {{10}^{8}}\] m/s |
| C. | \[1.78\times {{10}^{8}}\] m/s |
| D. | \[1.50\times {{10}^{8}}\] m/s |
| Answer» C. \[1.78\times {{10}^{8}}\] m/s | |
| 3364. |
On a glass plate a light wave is incident at an angle of \[60{}^\circ \]. If the reflected and the refracted waves are mutually perpendicular, the refractive index of material is [MP PMT 1994; Haryana CEE 1996; KCET 1994; 2000] |
| A. | \[\frac{\sqrt{3}}{2}\] |
| B. | \[\sqrt{3}\] |
| C. | \[\frac{3}{2}\] |
| D. | \[\frac{1}{\sqrt{3}}\] |
| Answer» C. \[\frac{3}{2}\] | |
| 3365. |
When light enters from air to water, then its [MP PMT 1994; MP PET 1996] |
| A. | Frequency increases and speed decreases |
| B. | Frequency is same but the wavelength is smaller in water than in air |
| C. | Frequency is same but the wavelength in water is greater than in air |
| D. | Frequency decreases and wavelength is smaller in water than in air |
| Answer» C. Frequency is same but the wavelength in water is greater than in air | |
| 3366. |
In the adjoining diagram, a wavefront AB, moving in air is incident on a plane glass surface XY. Its position CD after refraction through a glass slab is shown also along with the normals drawn at A and D. The refractive index of glass with respect to air (\[\mu =1\]) will be equal to [CPMT 1988; DPMT 1999] |
| A. | \[\frac{\sin \theta }{\sin \theta '}\] |
| B. | \[\frac{\sin \theta }{\sin \varphi '}\] |
| C. | \[\frac{\sin \varphi '}{\sin \theta }\] |
| D. | \[\frac{AB}{CD}\] |
| Answer» C. \[\frac{\sin \varphi '}{\sin \theta }\] | |
| 3367. |
If the speed of light in vacuum is \[C\] \[m/\sec ,\] then the velocity of light in a medium of refractive index 1.5 [NCERT 1977; MP PMT 1984; CPMT 2002] |
| A. | Is 1.5 \[\times \] C |
| B. | Is C |
| C. | Is \[\frac{C}{1.5}\] |
| D. | Can have any velocity |
| Answer» D. Can have any velocity | |
| 3368. |
If \[{{\mu }_{_{0}}}\] be the relative permeability and \[{{K}_{0}}\] the dielectric constant of a medium, its refractive index is given by [MNR 1995] |
| A. | \[\frac{1}{\sqrt{{{\mu }_{0}}{{K}_{0}}}}\] |
| B. | \[\frac{1}{{{\mu }_{0}}{{K}_{0}}}\] |
| C. | \[\sqrt{{{\mu }_{0}}{{K}_{0}}}\] |
| D. | \[{{\mu }_{0}}{{K}_{0}}\] |
| Answer» D. \[{{\mu }_{0}}{{K}_{0}}\] | |
| 3369. |
The refractive index of a certain glass is 1.5 for light whose wavelength in vacuum is \[6000\,{AA}\]. The wavelength of this light when it passes through glass is [NCERT 1979; CBSE PMT 1993; MP PET 1985, 89] |
| A. | \[4000\text{ }{AA}\] |
| B. | \[6000\text{ }{AA}\] |
| C. | \[9000\text{ }{AA}\] |
| D. | \[15000\text{ }{AA}\] |
| Answer» B. \[6000\text{ }{AA}\] | |
| 3370. |
A beam of monochromatic blue light of wavelength \[4200\,{AA}\] in air travels in water (\[\mu =4/3\]). Its wavelength in water will be [MNR 1991; UPSEAT 2000] |
| A. | \[2800\,\,{AA}\] |
| B. | \[5600\,\,{AA}\] |
| C. | \[3150\,\,{AA}\] |
| D. | \[4000\,\,{AA}\] |
| Answer» D. \[4000\,\,{AA}\] | |
| 3371. |
If \[{{\varepsilon }_{0}}\] and \[{{\mu }_{0}}\] are respectively, the electric permittivity and the magnetic permeability of free space, \[\varepsilon \] and \[\mu \] the corresponding quantities in a medium, the refractive index of the medium is [IIT-JEE 1982; MP PET 1995; CBSE PMT 1997] |
| A. | \[\sqrt{\frac{\mu \varepsilon }{{{\mu }_{0}}{{\varepsilon }_{0}}}}\] |
| B. | \[\frac{\mu \,\varepsilon }{{{\mu }_{0}}{{\varepsilon }_{0}}}\] |
| C. | \[\sqrt{\frac{{{\mu }_{0}}{{\varepsilon }_{0}}}{\mu \varepsilon }}\] |
| D. | \[\sqrt{\frac{\mu {{\mu }_{0}}}{\varepsilon \,{{\varepsilon }_{0}}}}\] |
| Answer» B. \[\frac{\mu \,\varepsilon }{{{\mu }_{0}}{{\varepsilon }_{0}}}\] | |
| 3372. |
A ray of light travelling inside a rectangular glass block of refractive index \[\sqrt{2}\] is incident on the glass-air surface at an angle of incidence of \[45{}^\circ \]. The refractive index of air is 1. Under these conditions the ray [CPMT 1972] |
| A. | Will emerge into the air without any deviation |
| B. | Will be reflected back into the glass |
| C. | Will be absorbed |
| D. | Will emerge into the air with an angle of refraction equal to 90° |
| Answer» E. | |
| 3373. |
For a colour of light the wavelength for air is \[6000{AA}\] and in water the wavelength is \[4500{AA}\]. Then the speed of light in water will be |
| A. | \[5.\times {{10}^{14}}\,m/s\] |
| B. | \[2.25\times {{10}^{8}}\]m/s |
| C. | \[4.0\times {{10}^{8}}\]m/s |
| D. | Zero |
| Answer» C. \[4.0\times {{10}^{8}}\]m/s | |
| 3374. |
When light travels from air to water and from water to glass, again from glass to \[C{{O}_{2}}\] gas and finally through air. The relation between their refractive indices will be given by |
| A. | \[_{a}{{n}_{w}}\times {{\,}_{w}}{{n}_{gl}}\times {{\,}_{gl}}{{n}_{gas}}\times {{\,}_{gas}}{{n}_{a}}=1\] |
| B. | \[_{a}{{n}_{w}}\times {{\,}_{w}}{{n}_{gl}}\times {{\,}_{gas}}{{n}_{gl}}\times {{\,}_{gl}}{{n}_{a}}=1\] |
| C. | \[_{a}{{n}_{w}}\,\times {{\,}_{w}}{{n}_{gl}}\,\times {{\,}_{gl}}{{n}_{gas}}=1\] |
| D. | There is no such relation |
| Answer» B. \[_{a}{{n}_{w}}\times {{\,}_{w}}{{n}_{gl}}\times {{\,}_{gas}}{{n}_{gl}}\times {{\,}_{gl}}{{n}_{a}}=1\] | |
| 3375. |
Ray optics fails when |
| A. | The size of the obstacle is 5 cm |
| B. | The size of the obstacle is 3 cm |
| C. | The size of the obstacle is less than the wavelength of light |
| D. | (a) and (b) both |
| Answer» D. (a) and (b) both | |
| 3376. |
The wavelength of light diminishes \[\mu \] times (\[\mu =1.33\] for water) in a medium. A diver from inside water looks at an object whose natural colour is green. He sees the object as [CPMT 1990; MNR 1998] |
| A. | Green |
| B. | Blue |
| C. | Yellow |
| D. | Red |
| Answer» B. Blue | |
| 3377. |
If \[_{i}{{\mu }_{j}}\] represents refractive index when a light ray goes from medium i to medium j, then the product \[_{2}{{\mu }_{1}}\times {{\,}_{3}}{{\mu }_{2}}\times {{\,}_{4}}{{\mu }_{3}}\] is equal to [CBSE PMT 1990] |
| A. | \[_{3}{{\mu }_{1}}\] |
| B. | \[_{3}{{\mu }_{2}}\] |
| C. | \[\frac{1}{_{1}{{\mu }_{4}}}\] |
| D. | \[_{4}{{\mu }_{2}}\] |
| Answer» D. \[_{4}{{\mu }_{2}}\] | |
| 3378. |
The refractive indices of glass and water w.r.t. air are 3/2 and 4/3 respectively. The refractive index of glass w.r.t. water will be [MNR 1990; JIPMER 1997, 2000; MP PET 2000] |
| A. | 8/9 |
| B. | 9/8 |
| C. | 7/6 |
| D. | None of these |
| Answer» C. 7/6 | |
| 3379. |
Immiscible transparent liquids A, B, C, D and E are placed in a rectangular container of glass with the liquids making layers according to their densities. The refractive index of the liquids are shown in the adjoining diagram. The container is illuminated from the side and a small piece of glass having refractive index 1.61 is gently dropped into the liquid layer. The glass piece as it descends downwards will not be visible in [CPMT 1986] |
| A. | Liquid A and B only |
| B. | Liquid C only |
| C. | Liquid D and E only |
| D. | Liquid A, B, D and E |
| Answer» C. Liquid D and E only | |
| 3380. |
The refractive index of a piece of transparent quartz is the greatest for [MP PET 1985, 94] |
| A. | Red light |
| B. | Violet light |
| C. | Green light |
| D. | Yellow light |
| Answer» C. Green light | |
| 3381. |
The length of the optical path of two media in contact of length \[{{d}_{1}}\] and \[{{d}_{2}}\] of refractive indices \[\]\[{{\mu }_{1}}\] and \[{{\mu }_{2}}\] respectively, is |
| A. | \[{{\mu }_{1}}{{d}_{1}}+{{\mu }_{2}}{{d}_{2}}\] |
| B. | \[{{\mu }_{1}}{{d}_{2}}+{{\mu }_{2}}{{d}_{1}}\] |
| C. | \[\frac{{{d}_{1}}{{d}_{2}}}{{{\mu }_{1}}{{\mu }_{2}}}\] |
| D. | \[\frac{{{d}_{1}}+{{d}_{2}}}{{{\mu }_{1}}{{\mu }_{2}}}\] |
| Answer» B. \[{{\mu }_{1}}{{d}_{2}}+{{\mu }_{2}}{{d}_{1}}\] | |
| 3382. |
Light takes 8 min 20 sec to reach from sun on the earth. If the whole atmosphere is filled with water, the light will take the time (\[_{a}{{\mu }_{w}}=4/3\]) |
| A. | 8 min 20 sec |
| B. | 8 min |
| C. | 6 min 11 sec |
| D. | 11 min 6 sec |
| Answer» E. | |
| 3383. |
A vessel of depth 2d cm is half filled with a liquid of refractive index \[{{\mu }_{1}}\] and the upper half with a liquid of refractive index \[{{\mu }_{2}}\]. The apparent depth of the vessel seen perpendicularly is [SCRA 1994] |
| A. | \[d\,\left( \frac{{{\mu }_{1}}{{\mu }_{2}}}{{{\mu }_{1}}+{{\mu }_{2}}} \right)\] |
| B. | \[d\,\left( \frac{1}{{{\mu }_{1}}}+\frac{1}{{{\mu }_{2}}} \right)\] |
| C. | \[2d\,\left( \frac{1}{{{\mu }_{1}}}+\frac{1}{{{\mu }_{2}}} \right)\] |
| D. | \[2d\,\left( \frac{1}{{{\mu }_{1}}{{\mu }_{2}}} \right)\] |
| Answer» C. \[2d\,\left( \frac{1}{{{\mu }_{1}}}+\frac{1}{{{\mu }_{2}}} \right)\] | |
| 3384. |
A rectangular tank of depth 8 meter is full of water (\[\mu =4/3\]), the bottom is seen at the depth [MP PMT 1987] |
| A. | 6 m |
| B. | 8/3 m |
| C. | 8 cm |
| D. | 10 cm |
| Answer» B. 8/3 m | |
| 3385. |
A monochromatic beam of light passes from a denser medium into a rarer medium. As a result [CPMT 1972] |
| A. | Its velocity increases |
| B. | Its velocity decreases |
| C. | Its frequency decreases |
| D. | Its wavelength decreases |
| Answer» B. Its velocity decreases | |
| 3386. |
Monochromatic light is refracted from air into the glass of refractive index \[\mu \]. The ratio of the wavelength of incident and refracted waves is [JIPMER 2000; MP PMT 1996, 2003] |
| A. | 1 : \[\mu \] |
| B. | 1 : \[{{\mu }^{2}}\] |
| C. | \[\mu \] : 1 |
| D. | 1 : 1 |
| Answer» D. 1 : 1 | |
| 3387. |
The ratio of the refractive index of red light to blue light in air is [CPMT 1978] |
| A. | Less than unity |
| B. | Equal to unity |
| C. | Greater than unity |
| D. | Less as well as greater than unity depending upon the experimental arrangement |
| Answer» B. Equal to unity | |
| 3388. |
A thin lens made of glass of refractive index m = 1.5 has a focal length equal to 12 cm in air. It is now immersed in water \[\left( \mu \,=\,\frac{4}{3} \right)\]. Its new focal length is [UPSEAT 2002] |
| A. | 48 cm |
| B. | 36 cm |
| C. | 24 cm |
| D. | 12 cm |
| Answer» B. 36 cm | |
| 3389. |
The unit of focal power of a lens is [KCET 2001] |
| A. | Watt |
| B. | Horse power |
| C. | Dioptre |
| D. | Lux |
| Answer» D. Lux | |
| 3390. |
A convex lens of focal length 25 cm and a concave lens of focal length 10 cm are joined together. The power of the combination will be [MP PMT 2001] |
| A. | ? 16 D |
| B. | + 16 D |
| C. | ? 6 D |
| D. | + 6 D |
| Answer» D. + 6 D | |
| 3391. |
A convex lens forms a real image of an object for its two different positions on a screen. If height of the image in both the cases be 8 cm and 2 cm, then height of the object is [KCET 2000, 01] |
| A. | 16 cm |
| B. | 8 cm |
| C. | 4 cm |
| D. | 2 cm |
| Answer» D. 2 cm | |
| 3392. |
The combination of a convex lens (f = 18 cm) and a thin concave lens (f = 9 cm) is [AMU (Engg.) 2001] |
| A. | A concave lens (f = 18 cm) |
| B. | A convex lens (f = 18 cm) |
| C. | A convex lens (f = 6 cm) |
| D. | A concave lens (f = 6 cm) |
| Answer» B. A convex lens (f = 18 cm) | |
| 3393. |
An object has image thrice of its original size when kept at 8 cm and 16 cm from a convex lens. Focal length of the lens is [UPSEAT 2001] |
| A. | 8 cm |
| B. | 16 cm |
| C. | Between 8 cm and 16 cm |
| D. | Less than 8 cm |
| Answer» D. Less than 8 cm | |
| 3394. |
A convex lens has a focal length f. It is cut into two parts along the dotted line as shown in the figure. The focal length of each part will be [MP PET 2000] |
| A. | \[\frac{f}{2}\] |
| B. | f |
| C. | \[\frac{3}{2}f\] |
| D. | 2f |
| Answer» E. | |
| 3395. |
The focal length of a convex lens is 10 cm and its refractive index is 1.5. If the radius of curvature of one surface is 7.5 cm, the radius of curvature of the second surface will be [MP PMT 2000] |
| A. | 7.5 cm |
| B. | 15.0 cm |
| C. | 75 cm |
| D. | 5.0 cm |
| Answer» C. 75 cm | |
| 3396. |
In a plano-convex lens the radius of curvature of the convex lens is 10 cm. If the plane side is polished, then the focal length will be (Refractive index = 1.5) [CBSE PMT 2000; BHU 2004] |
| A. | 10.5 cm |
| B. | 10 cm |
| C. | 5.5 cm |
| D. | 5 cm |
| Answer» C. 5.5 cm | |
| 3397. |
We combined a convex lens of focal length f1 and concave lens of focal lengths f2 and their combined focal length was F. The combination of these lenses will behave like a concave lens, if [KCET 2000] |
| A. | f1 > f2 |
| B. | f1 < f2 |
| C. | f1 = f2 |
| D. | f1 \[\le \] f2 |
| Answer» B. f1 < f2 | |
| 3398. |
A candle placed 25 cm from a lens, forms an image on a screen placed 75 cm on the other end of the lens. The focal length and type of the lens should be [KCET 2000] |
| A. | + 18.75 cm and convex lens |
| B. | - 18.75 cm and concave lens |
| C. | + 20.25 cm and convex lens |
| D. | - 20.25 cm and concave lens |
| Answer» B. - 18.75 cm and concave lens | |
| 3399. |
The relation between n1 and n2, if behaviour of light rays is as shown in figure is [KCET 2000] |
| A. | \[{{n}_{1}}>>{{n}_{2}}\] |
| B. | \[{{n}_{2}}>{{n}_{1}}\] |
| C. | \[{{n}_{1}}>{{n}_{2}}\] |
| D. | \[{{n}_{1}}={{n}_{2}}\] |
| Answer» C. \[{{n}_{1}}>{{n}_{2}}\] | |
| 3400. |
A double convex thin lens made of glass of refractive index 1.6 has radii of curvature 15 cm each. The focal length of this lens when immersed in a liquid of refractive index 1.63 is [UPSEAT 2000; Pb. PET 2004] |
| A. | - 407 cm |
| B. | 250 cm |
| C. | 125 cm |
| D. | 25 cm |
| Answer» B. 250 cm | |