JEE Main & Advanced Physics Ray Optics Question Bank

done Refraction of Light at Plane Surfaces Total Questions - 90

• question_answer1)
  To an observer on the earth the stars appear to twinkle. This can be ascribed to [CPMT 1972, 74; AFMC 1995]
  A)
             The fact that stars do not emit light continuously done clear
  B)
             Frequent absorption of star light by their own atmosphere done clear
  C)
             Frequent absorption of star light by the earth's atmosphere done clear
  D)
             The refractive index fluctuations in the earth's atmosphere done clear
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• question_answer2)
  The ratio of the refractive index of red light to blue light in air is                                 [CPMT 1978]
  A)
             Less than unity done clear
  B)
             Equal to unity done clear
  C)
             Greater than unity done clear
  D)
             Less as well as greater than unity depending upon the experimental arrangement done clear
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• question_answer3)
  The refractive index of a piece of transparent quartz is the greatest for                                 [MP PET 1985, 94]
  A)
             Red light                                 done clear
  B)
             Violet light done clear
  C)
             Green light                            done clear
  D)
             Yellow light done clear
  View Solution play_arrow

• question_answer4)
  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)
  \[4000\text{ }{AA}\]        done clear
  B)
  \[6000\text{ }{AA}\] done clear
  C)
  \[9000\text{ }{AA}\] done clear
  D)
  \[15000\text{ }{AA}\] done clear
  View Solution play_arrow

• question_answer5)
  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 done clear
  B)
             Frequency and wavelength done clear
  C)
             Frequency and velocity done clear
  D)
             Wavelength and velocity done clear
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• question_answer6)
  A light wave has a frequency of \[4\times {{10}^{14}}\]Hz and a wavelength of \[5\times {{10}^{-7}}\] meters in a medium. The refractive index of the medium is                                                                    [MP PMT 1989]
  A)
             1.5  done clear
  B)
             1.33 done clear
  C)
             1.0  done clear
  D)
             0.66 done clear
  View Solution play_arrow

• question_answer7)
  How much water should be filled in a container 21 cm in height, so that it appears half filled when viewed from the top of the container  (given that \[_{a}{{\mu }_{\omega }}=4/3\])  [MP PMT 1989]
  A)
             8.0 cm                                      done clear
  B)
             10.5 cm done clear
  C)
             12.0 cm                                    done clear
  D)
             None of the above done clear
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• question_answer8)
  Light of different colours propagates through air
  A)
             With the velocity of air     done clear
  B)
             With different velocities done clear
  C)
             With the velocity of sound done clear
  D)
             Having the equal velocities done clear
  View Solution play_arrow

• question_answer9)
  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 : \[\mu \]                            done clear
  B)
             1 : \[{{\mu }^{2}}\] done clear
  C)
             \[\mu \] : 1                            done clear
  D)
             1 : 1 done clear
  View Solution play_arrow

• question_answer10)
  A monochromatic beam of light passes from a denser medium into a rarer medium. As a result [CPMT 1972]
  A)
             Its velocity increases         done clear
  B)
             Its velocity decreases done clear
  C)
             Its frequency decreases  done clear
  D)
             Its wavelength decreases done clear
  View Solution play_arrow

• question_answer11)
  Refractive index for a material for infrared light is [CPMT 1984]
  A)
             Equal to that of ultraviolet light done clear
  B)
             Less than for ultraviolet light done clear
  C)
             Equal to that for red colour of light done clear
  D)
             Greater than that for ultraviolet light done clear
  View Solution play_arrow

• question_answer12)
  The index of refraction of diamond is 2.0, velocity of light in diamond in cm/second is approximately [CPMT 1975; MNR 1987; UPSEAT 2000]
  A)
             \[6\times {{10}^{10}}\]     done clear
  B)
             \[3.0\times {{10}^{10}}\] done clear
  C)
             \[2\times {{10}^{10}}\]     done clear
  D)
             \[1.5\times {{10}^{10}}\] done clear
  View Solution play_arrow

• question_answer13)
  A beam of light propagating in medium A with index of refraction n  passes across an interface into medium B with index of refraction n. The angle of incidence is greater than the angle of refraction; v and v denotes the speed of light in A and B. Then which of the following is true
  A)
             v > v  and n > n done clear
  B)
             v > v  and  n < n done clear
  C)
             v < v  and  n > n done clear
  D)
             v < v  and  n < n done clear
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• question_answer14)
  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                                            done clear
  B)
             8/3 m done clear
  C)
             8 cm                                          done clear
  D)
             10 cm done clear
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• question_answer15)
  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)
             \[d\,\left( \frac{{{\mu }_{1}}{{\mu }_{2}}}{{{\mu }_{1}}+{{\mu }_{2}}} \right)\]        done clear
  B)
             \[d\,\left( \frac{1}{{{\mu }_{1}}}+\frac{1}{{{\mu }_{2}}} \right)\] done clear
  C)
             \[2d\,\left( \frac{1}{{{\mu }_{1}}}+\frac{1}{{{\mu }_{2}}} \right)\]  done clear
  D)
             \[2d\,\left( \frac{1}{{{\mu }_{1}}{{\mu }_{2}}} \right)\] done clear
  View Solution play_arrow

• question_answer16)
  A beam of light is converging towards a point \[I\] on a screen. A plane glass plate whose thickness in the direction of the beam = \[t\], refractive index = \[\mu \], is introduced in the path of the beam. The convergence point is shifted by [MNR 1987]
  A)
             \[t\,\left( 1-\frac{1}{\mu } \right)\] away                     done clear
  B)
             \[t\,\left( 1+\frac{1}{\mu } \right)\] away done clear
  C)
             \[t\,\left( 1-\frac{1}{\mu } \right)\] nearer                  done clear
  D)
             \[t\,\left( 1+\frac{1}{\mu } \right)\] nearer done clear
  View Solution play_arrow

• question_answer17)
  Light travels through a glass plate of thickness t and having refractive index n. If c is the velocity of light in vacuum, the time taken by the light to travel this thickness of glass is  [NCERT 1976; MP PET 1994; CBSE PMT 1996; KCET 1994; MP PMT 1999, 2001]
  A)
             \[\frac{t}{nc}\]                     done clear
  B)
             \[tnc\] done clear
  C)
             \[\frac{nt}{c}\]                     done clear
  D)
             \[\frac{tc}{n}\] done clear
  View Solution play_arrow

• question_answer18)
  When a light wave goes from air into water,  the quality that remains unchanged is its [AMU 1995; MNR 1985, 95; KCET 1993; CPMT 1990, 97; MP PET 1991, 2000, 02; UPSEAT 1999, 2000; AFMC 1993, 98, 2003; RPET 1996, 2000, 03; RPMT 1999, 2000; DCE 2001; BHU 2001]
  A)
             Speed                                      done clear
  B)
             Amplitude done clear
  C)
             Frequency                             done clear
  D)
             Wavelength done clear
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• question_answer19)
  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                           done clear
  B)
             8 min done clear
  C)
             6 min 11 sec                           done clear
  D)
             11 min 6 sec done clear
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• question_answer20)
  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)
             \[{{\mu }_{1}}{{d}_{1}}+{{\mu }_{2}}{{d}_{2}}\]        done clear
  B)
             \[{{\mu }_{1}}{{d}_{2}}+{{\mu }_{2}}{{d}_{1}}\] done clear
  C)
             \[\frac{{{d}_{1}}{{d}_{2}}}{{{\mu }_{1}}{{\mu }_{2}}}\]        done clear
  D)
             \[\frac{{{d}_{1}}+{{d}_{2}}}{{{\mu }_{1}}{{\mu }_{2}}}\] done clear
  View Solution play_arrow

• question_answer21)
  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             done clear
  B)
             Liquid C only done clear
  C)
             Liquid D and E only done clear
  D)
             Liquid A, B, D and E done clear
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• question_answer22)
  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 done clear
  B)
             9/8 done clear
  C)
             7/6 done clear
  D)
             None of these done clear
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• question_answer23)
  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)
             \[_{3}{{\mu }_{1}}\]           done clear
  B)
             \[_{3}{{\mu }_{2}}\] done clear
  C)
             \[\frac{1}{_{1}{{\mu }_{4}}}\]                                            done clear
  D)
             \[_{4}{{\mu }_{2}}\] done clear
  View Solution play_arrow

• question_answer24)
  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                                      done clear
  B)
             Blue done clear
  C)
             Yellow                                      done clear
  D)
             Red done clear
  View Solution play_arrow

• question_answer25)
  Ray optics fails when
  A)
             The size of the obstacle is 5 cm done clear
  B)
             The size of the obstacle is 3 cm done clear
  C)
             The size of the obstacle is less than the wavelength of light done clear
  D)
             (a) and (b) both done clear
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• question_answer26)
  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)
             \[_{a}{{n}_{w}}\times {{\,}_{w}}{{n}_{gl}}\times {{\,}_{gl}}{{n}_{gas}}\times {{\,}_{gas}}{{n}_{a}}=1\] done clear
  B)
             \[_{a}{{n}_{w}}\times {{\,}_{w}}{{n}_{gl}}\times {{\,}_{gas}}{{n}_{gl}}\times {{\,}_{gl}}{{n}_{a}}=1\] done clear
  C)
             \[_{a}{{n}_{w}}\,\times {{\,}_{w}}{{n}_{gl}}\,\times {{\,}_{gl}}{{n}_{gas}}=1\] done clear
  D)
             There is no such relation done clear
  View Solution play_arrow

• question_answer27)
  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)
  \[5.\times {{10}^{14}}\,m/s\]                                            done clear
  B)
  \[2.25\times {{10}^{8}}\]m/s done clear
  C)
  \[4.0\times {{10}^{8}}\]m/s   done clear
  D)
  Zero done clear
  View Solution play_arrow

• question_answer28)
  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 done clear
  B)
  Will be reflected back into the glass done clear
  C)
  Will be absorbed done clear
  D)
  Will emerge into the air with an angle of refraction equal to 90° done clear
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• question_answer29)
  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)
             \[\sqrt{\frac{\mu \varepsilon }{{{\mu }_{0}}{{\varepsilon }_{0}}}}\]              done clear
  B)
             \[\frac{\mu \,\varepsilon }{{{\mu }_{0}}{{\varepsilon }_{0}}}\] done clear
  C)
             \[\sqrt{\frac{{{\mu }_{0}}{{\varepsilon }_{0}}}{\mu \varepsilon }}\]              done clear
  D)
             \[\sqrt{\frac{\mu {{\mu }_{0}}}{\varepsilon \,{{\varepsilon }_{0}}}}\] done clear
  View Solution play_arrow

• question_answer30)
  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)
  \[2800\,\,{AA}\]                done clear
  B)
  \[5600\,\,{AA}\] done clear
  C)
  \[3150\,\,{AA}\]                done clear
  D)
  \[4000\,\,{AA}\] done clear
  View Solution play_arrow

• question_answer31)
  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)
             \[\frac{1}{\sqrt{{{\mu }_{0}}{{K}_{0}}}}\]                     done clear
  B)
   \[\frac{1}{{{\mu }_{0}}{{K}_{0}}}\] done clear
  C)
             \[\sqrt{{{\mu }_{0}}{{K}_{0}}}\]                                        done clear
  D)
             \[{{\mu }_{0}}{{K}_{0}}\] done clear
  View Solution play_arrow

• question_answer32)
  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              done clear
  B)
             Is C done clear
  C)
             Is \[\frac{C}{1.5}\]              done clear
  D)
             Can have any velocity done clear
  View Solution play_arrow

• question_answer33)
  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)
             \[\frac{\sin \theta }{\sin \theta '}\] done clear
  B)
             \[\frac{\sin \theta }{\sin \varphi '}\] done clear
  C)
             \[\frac{\sin \varphi '}{\sin \theta }\] done clear
  D)
             \[\frac{AB}{CD}\] done clear
  View Solution play_arrow

• question_answer34)
  When light enters from air to water, then its  [MP PMT 1994; MP PET 1996]
  A)
             Frequency increases and speed decreases done clear
  B)
             Frequency is same but the wavelength is smaller in water than in air done clear
  C)
             Frequency is same but the wavelength in water is greater than in air done clear
  D)
             Frequency decreases and wavelength is smaller in water than in air done clear
  View Solution play_arrow

• question_answer35)
  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)
  \[\frac{\sqrt{3}}{2}\]         done clear
  B)
  \[\sqrt{3}\] done clear
  C)
  \[\frac{3}{2}\]                       done clear
  D)
  \[\frac{1}{\sqrt{3}}\] done clear
  View Solution play_arrow

• question_answer36)
  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                                            done clear
  B)
             \[2.25\times {{10}^{8}}\] m/s done clear
  C)
             \[1.78\times {{10}^{8}}\] m/s                                            done clear
  D)
             \[1.50\times {{10}^{8}}\] m/s done clear
  View Solution play_arrow

• question_answer37)
  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)
  \[4000\,\,{AA}\]                done clear
  B)
  \[5000\,\,{AA}\] done clear
  C)
  \[6000\,\,{AA}\] done clear
  D)
  \[5500\,\,{AA}\] done clear
  View Solution play_arrow

• question_answer38)
  Light of wavelength is \[7200\,{AA}\] in air. It  has a wavelength in glass (\[\mu =1.5\]) equal to                                                     [DCE 1999]
  A)
  \[7200\,\,{AA}\]                done clear
  B)
  \[4800\,\,{AA}\] done clear
  C)
  \[10800\,\,{AA}\]              done clear
  D)
  \[7201.5\,\,{AA}\] done clear
  View Solution play_arrow

• question_answer39)
  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 done clear
  B)
             The wavelength of blue light is smaller than the wavelength of orange light done clear
  C)
             The frequency of green light is greater than the frequency of blue ligh done clear
  D)
             The frequency of violet light is greater than the frequency of blue light done clear
  View Solution play_arrow

• question_answer40)
  Which of the following is a correct relation      [MP PET 1997]
  A)
             \[_{a}{{\mu }_{r}}={{\,}_{a}}{{\mu }_{w}}\times \,{{\,}_{r}}{{\mu }_{\omega }}\]   done clear
  B)
             \[_{a}{{\mu }_{r}}\times {{\,}_{r}}{{\mu }_{w}}={{\,}_{w}}{{\mu }_{a}}\] done clear
  C)
             \[_{a}{{\mu }_{r}}\times {{\,}_{r}}{{\mu }_{a}}=0\] done clear
  D)
             \[_{a}{{\mu }_{r}}/{{\,}_{w}}{{\mu }_{r}}={{\,}_{a}}{{\mu }_{w}}\] done clear
  View Solution play_arrow

• question_answer41)
  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 \[s\]  done clear
  B)
             \[0.167\times {{10}^{-7}}\]\[s\] done clear
  C)
             \[2.5\times {{10}^{-10}}\]\[s\]                                          done clear
  D)
             \[1.0\times {{10}^{-10}}\]\[s\] done clear
  View Solution play_arrow

• question_answer42)
  The distance travelled by light in glass (refractive index =1.5)  in a nanosecond will be                     [MP PET 1999]
  A)
             45 cm                                       done clear
  B)
             40 cm done clear
  C)
             30 cm                                       done clear
  D)
             20 cm done clear
  View Solution play_arrow

• question_answer43)
  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 done clear
  B)
             Its wavelength increases but frequency remains unchanged done clear
  C)
             Its wavelength decreases but frequency remains unchanged done clear
  D)
             Its wavelength and frequency both decrease done clear
  View Solution play_arrow

• question_answer44)
  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                                           done clear
  B)
             \[\frac{9}{10}\] done clear
  C)
             \[\frac{10}{9}\]                    done clear
  D)
             1.5v done clear
  View Solution play_arrow

• question_answer45)
  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                                          done clear
  B)
             n / h done clear
  C)
             h     done clear
  D)
             hn done clear
  View Solution play_arrow

• question_answer46)
  On heating a liquid, the refractive index generally [KCET 1994]
  A)
             Decreases done clear
  B)
             Increases or decreases depending on the rate of heating done clear
  C)
             Does not change done clear
  D)
             Increases done clear
  View Solution play_arrow

• question_answer47)
  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)
             \[\hat{i}\,.\,\hat{n}=\mu (\hat{r}\,.\,\hat{n})\]                          done clear
  B)
             \[\hat{i}\times \hat{n}=\mu (\hat{n}\times \hat{r})\] done clear
  C)
             \[\hat{i}\times \hat{n}=\mu (\hat{r}\times \hat{n})\]         done clear
  D)
             \[\mu (\hat{i}\times \hat{n})=\hat{r}\times \hat{n}\] done clear
  View Solution play_arrow

• question_answer48)
  The bottom of a container filled with liquid appear slightly raised because of                                       [RPMT 1997]
  A)
             Refraction                              done clear
  B)
             Interference done clear
  C)
             Diffraction                              done clear
  D)
             Reflection done clear
  View Solution play_arrow

• question_answer49)
  The speed of light in air is \[3\times {{10}^{8}}\,\,m/s\]. What will be its speed in diamond whose refractive index is 2.4 [KCET 1993]
  A)
             \[3\times {{10}^{8}}\] \[m/s\]                                           done clear
  B)
             332 \[m/s\] done clear
  C)
             \[1.25\times {{10}^{8}}\] m/s                                            done clear
  D)
             \[7.2\times {{10}^{8}}\] \[m/s\] done clear
  View Solution play_arrow

• question_answer50)
  Time taken by the sunlight to pass through a window of thickness 4 mm whose refractive index is 1.5 is [CBSE PMT 1993]
  A)
             \[2\times {{10}^{-8}}\] sec      done clear
  B)
             \[2\times {{10}^{8}}\] sec done clear
  C)
             \[2\times {{10}^{-11}}\] sec    done clear
  D)
             \[2\times {{10}^{11}}\] sec done clear
  View Solution play_arrow

• question_answer51)
  Ray optics is valid, when characteristic  dimensions are [CBSE PMT 1994; CPMT 2001]
  A)
             Of the same order as the wavelength of light done clear
  B)
             Much smaller than the wavelength of light done clear
  C)
             Of the order of one millimetre done clear
  D)
             Much larger than the wavelength of light done clear
  View Solution play_arrow

• question_answer52)
  The refractive index of water is 1.33. What will be the speed of light in water      [CBSE PMT 1996; KCET 1998]
  A)
             \[3\times {{10}^{8}}\] \[m/s\]                                           done clear
  B)
             \[2.25\times {{10}^{8}}\] \[m/s\] done clear
  C)
             \[4\times {{10}^{8}}\] \[m/s\]                                           done clear
  D)
             \[1.33\times {{10}^{8}}\] m/s done clear
  View Solution play_arrow

• question_answer53)
  The time required to pass the light through a glass slab of 2 mm thick is (\[{{\mu }_{glass}}=1.5\]) [AFMC 1997; MH CET 2002, 04]
  A)
             \[{{10}^{-5}}\,s\]                 done clear
  B)
             \[{{10}^{-11}}\]\[s\] done clear
  C)
             \[{{10}^{-9}}\]s                    done clear
  D)
             \[{{10}^{-13}}\]\[s\] done clear
  View Solution play_arrow

• question_answer54)
  The refractive index of water with respect to air is 4 / 3 and the refractive index of glass with respect to air is 3/2. The refractive index of water with respect to glass is [BHU 1997; JIPMER 2000]
  A)
             \[\frac{9}{8}\]                       done clear
  B)
             \[\frac{8}{9}\] done clear
  C)
             \[\frac{1}{2}\]                       done clear
  D)
             2 done clear
  View Solution play_arrow

• question_answer55)
  Electromagnetic radiation of frequency n, wavelength \[\lambda \], travelling with velocity v in air, enters a glass slab of refractive index \[\mu \]. The frequency, wavelength and velocity of light in the glass slab will be respectively [CBSE PMT 1997]
  A)
             \[\frac{n}{\mu }\,,\,\frac{\lambda }{\mu },\,\frac{v}{\mu }\]            done clear
  B)
             \[n,\frac{\lambda }{\mu },\frac{v}{\mu }\] done clear
  C)
             \[n\,,\,\lambda \,,\,\frac{\text{v}}{\mu }\]                 done clear
  D)
             \[\frac{n}{\mu }\,,\,\,\]\[\frac{\lambda }{\mu }\,,\,v\] done clear
  View Solution play_arrow

• question_answer56)
  What is the time taken (in seconds) to cross a glass of thickness 4 mm and \[\mu \]= 3 by light    [BHU 1998; Pb. PMT 1999, 2001; MH CET 2000; MP PET 2001]
  A)
             \[4\times {{10}^{-11}}\]   done clear
  B)
             \[2\times {{10}^{-11}}\] done clear
  C)
             \[16\times {{10}^{-11}}\] done clear
  D)
             \[8\times {{10}^{-10}}\] done clear
  View Solution play_arrow

• question_answer57)
  A plane glass slab is kept over various coloured letters, the letter which appears least raised is [J & K CET 2004; BHU 1998, 05]
  A)
             Blue                                          done clear
  B)
             Violet done clear
  C)
             Green                                      done clear
  D)
             Red done clear
  View Solution play_arrow

• question_answer58)
  A ray of light is incident on the surface of separation of a medium at an angle \[45{}^\circ \] and is refracted in the medium at an angle \[30{}^\circ \]. What will be the velocity of light in the medium [AFMC 1998; MH CET (Med.) 1999]
  A)
  \[1.96\times {{10}^{8}}\] m/s                                            done clear
  B)
  \[2.12\times {{10}^{8}}\] \[m/s\] done clear
  C)
  \[3.18\times {{10}^{8}}\]\[m/s\]                                      done clear
  D)
  \[3.33\times {{18}^{8}}\]\[m/s\] done clear
  View Solution play_arrow

• question_answer59)
  Absolute refractive indices of glass and water are \[\frac{3}{2}\] and \[\frac{4}{3}\].  The ratio of velocity of light in glass and water will be [UPSEAT 1999]
  A)
             4 : 3                                           done clear
  B)
             8 : 7 done clear
  C)
             8 : 9                                           done clear
  D)
             3 : 4 done clear
  View Solution play_arrow

• question_answer60)
  The ratio of thickness of plates of two transparent mediums A and B is 6 : 4.  If light takes equal time in passing through them, then refractive index of B with respect to A will be [UPSEAT 1999]  
  A)
             1.4 done clear
  B)
             1.5 done clear
  C)
             1.75                                           done clear
  D)
             1.33 done clear
  View Solution play_arrow

• question_answer61)
  The refractive index of water and glass with respect to air is 1.3 and 1.5 respectively.  Then the refractive index of glass with respect to water is                                   [MH CET (Med.) 1999]
  A)
             \[\frac{2.6}{1.5}\]               done clear
  B)
             \[\frac{1.5}{2.6}\] done clear
  C)
             \[\frac{1.3}{1.5}\]               done clear
  D)
             \[\frac{1.5}{1.3}\] done clear
  View Solution play_arrow

• question_answer62)
  A tank is filled with benzene to a height of 120 mm. The apparent depth of a needle lying at a bottom of the tank is measured by a microscope to be 80 mm.  The refractive index of benzene is                                       [Pb. PMT 1999]
  A)
             1.5 done clear
  B)
             2.5 done clear
  C)
             3.5  done clear
  D)
             4.5 done clear
  View Solution play_arrow

• question_answer63)
  Each quarter of a vessel of depth H is filled with liquids of the refractive indices \[{{n}_{1}},{{n}_{2}},{{n}_{3}}\,\,and\,\,{{n}_{4}}\] from the bottom respectively.  The apparent depth of the vessel when looked normally is        [AMU (Engg.) 2000]
  A)
  \[\frac{H({{n}_{1}}+{{n}_{2}}+{{n}_{3}}+{{n}_{4}})}{4}\]      done clear
  B)
  \[\frac{H\left( \frac{1}{{{n}_{1}}}+\frac{1}{{{n}_{2}}}+\frac{1}{{{n}_{3}}}+\frac{1}{{{n}_{4}}} \right)}{4}\] done clear
  C)
  \[\frac{({{n}_{1}}+{{n}_{2}}+{{n}_{3}}+{{n}_{4}})}{4H}\]      done clear
  D)
  \[\frac{H\left( \frac{1}{{{n}_{1}}}+\frac{1}{{{n}_{2}}}+\frac{1}{{{n}_{3}}}+\frac{1}{{{n}_{4}}} \right)}{2}\] done clear
  View Solution play_arrow

• question_answer64)
  A ray of light passes through four transparent media with refractive indices \[{{\mu }_{1}}.{{\mu }_{2}}{{\mu }_{3}},\text{ and}\,{{\mu }_{4}}\] as shown in the figure.  The surfaces of all media are parallel.  If the emergent ray CD is parallel to the incident ray AB, we must have [IIT-JEE (Screening) 2001]
  A)
             \[{{\mu }_{1}}={{\mu }_{2}}\] done clear
  B)
             \[{{\mu }_{2}}={{\mu }_{3}}\] done clear
  C)
             \[{{\mu }_{3}}={{\mu }_{4}}\] done clear
  D)
             \[{{\mu }_{4}}={{\mu }_{1}}\] done clear
  View Solution play_arrow

• question_answer65)
  The reason of seeing the Sun a little before the sunrise is [MP PMT 2001; Orissa JEE 2003]
  A)
             Reflection of the light       done clear
  B)
             Refraction of the light done clear
  C)
             Scattering of the light        done clear
  D)
             Dispersion of the light done clear
  View Solution play_arrow

• question_answer66)
  An underwater swimmer is at a depth of 12 m below the surface of water.  A bird is at a height of 18 m from the surface of water, directly above his eyes.  For the swimmer the bird appears to be at a distance from the surface of water equal to (Refractive Index of water is 4/3) [KCET (Engg.) 2001]
  A)
             24 m                                         done clear
  B)
             12 m done clear
  C)
             18 m                                         done clear
  D)
             9 m done clear
  View Solution play_arrow

• question_answer67)
  The optical path of a monochromatic light is same if it goes through 4.0 cm of glass or 4.5 cm of water.  If the refractive index of glass is 1.53, the refractive index of the water is [UPSEAT 2002]
  A)
             1.30                                           done clear
  B)
             1.36 done clear
  C)
             1.42                                           done clear
  D)
             1.46 done clear
  View Solution play_arrow

• question_answer68)
  Which of the following statement is true      [Orissa JEE 2002]
  A)
             Velocity of light is constant in all media                         done clear
  B)
             Velocity of light in vacuum is maximum done clear
  C)
             Velocity of light is same in all reference frames done clear
  D)
             Laws of nature have identical form in all reference frames done clear
  View Solution play_arrow

• question_answer69)
  A ray of light is incident on a transparent glass slab of refractive index 1.62.  The reflected and the refracted rays are mutually perpendicular. The angle of incidence is [MP PET 2002]
  A)
             58.3o                                         done clear
  B)
             50o done clear
  C)
             35o done clear
  D)
             30o done clear
  View Solution play_arrow

• question_answer70)
  A microscope is focussed on a coin lying at the bottom of a beaker. The microscope is now raised up by 1 cm. To what depth should the water be poured into the beaker so that coin is again in focus? (Refractive index of water is\[\frac{4}{3}\]) [BHU 2003]
  A)
             1 cm                                          done clear
  B)
             \[\frac{4}{3}\] cm done clear
  C)
             3 cm                                          done clear
  D)
             4 cm done clear
  View Solution play_arrow

• question_answer71)
  Velocity of light in glass whose refractive index with respect to air is 1.5 is \[2\times {{10}^{8}}m/s\] and in certain liquid the velocity of light found to be \[2.5\times {{10}^{8}}m/s\]. The refractive index of the liquid with respect to air is [CPMT 1978; MP PET/PMT 1988]
  A)
  0.64                                           done clear
  B)
  0.80 done clear
  C)
  1.20                                           done clear
  D)
  1.44 done clear
  View Solution play_arrow

• question_answer72)
  Stars are twinkling due to                                          [CPMT 1997]
  A)
             Diffraction                              done clear
  B)
             Reflection done clear
  C)
             Refraction                              done clear
  D)
             Scattering done clear
  View Solution play_arrow

• question_answer73)
  A thin oil layer floats on water. A ray of light making an angle of incidence of \[40{}^\circ \] shines on oil layer. The angle of refraction of light ray in water  is (\[{{\mu }_{oil}}=1.45,\,{{\mu }_{water}}=1.33\]) [MP PMT 1993]
  A)
  \[36.1{}^\circ \]                                       done clear
  B)
  \[44.5{}^\circ \] done clear
  C)
  \[26.8{}^\circ \] done clear
  D)
  \[28.9{}^\circ \] done clear
  View Solution play_arrow

• question_answer74)
  An object is immersed in a fluid. In order that the object becomes invisible, it should  [AIIMS 2004]
  A)
             Behave as a perfect reflector done clear
  B)
             Absorb all light falling on it done clear
  C)
             Have refractive index one done clear
  D)
             Have refractive index exactly matching with that of the surrounding fluid done clear
  View Solution play_arrow

• question_answer75)
  When light travels from glass to air, the incident angle is \[{{\theta }_{1}}\] and the refracted angle is \[{{\theta }_{2}}\]. The true relation is [Orissa PMT 2004]
  A)
             \[{{\theta }_{1}}={{\theta }_{2}}\]                                   done clear
  B)
             \[{{\theta }_{1}}<{{\theta }_{2}}\] done clear
  C)
             \[{{\theta }_{1}}>{{\theta }_{2}}\]                                   done clear
  D)
             Not predictable done clear
  View Solution play_arrow

• question_answer76)
  Velocity of light in a medium is \[1.5\times {{10}^{8}}m/s.\] Its refractive index will be                                    [Pb. PET 2000]
  A)
             8     done clear
  B)
             6 done clear
  C)
             4     done clear
  D)
             2 done clear
  View Solution play_arrow

• question_answer77)
  The frequency of a light ray is \[6\times {{10}^{14}}Hz.\]Its frequency when it propagates in a medium of refractive index 1.5, will be                                          [MP PMT 2000; DPMT 2003; Pb PMT 2003; MH CET 2004]
  A)
             \[1.67\times {{10}^{14}}Hz\]  done clear
  B)
             \[9.10\times {{10}^{14}}Hz\] done clear
  C)
             \[6\times {{10}^{14}}Hz\]        done clear
  D)
             \[4\times {{10}^{14}}Hz\] done clear
  View Solution play_arrow

• question_answer78)
  The refractive indices of water and glass with respect to air are 1.2 and 1.5 respectively. The refractive index of glass with respect to water is                                                     [Pb. PET 2002]
  A)
             0.6  done clear
  B)
             0.8 done clear
  C)
             1.25                                           done clear
  D)
             1.75 done clear
  View Solution play_arrow

• question_answer79)
  The wavelength of sodium light in air is \[5890\,{AA}\]. The velocity of light in air is \[3\times {{10}^{8}}m{{s}^{-1}}.\] The wavelength of light in a glass of refractive index 1.6 would be close to  [DCE 2003]
  A)
  \[5890\,\,{AA}\]                done clear
  B)
  \[3681\,\,{AA}\] done clear
  C)
  \[9424\,\,{AA}\]                done clear
  D)
  \[15078\,\,{AA}\] done clear
  View Solution play_arrow

• question_answer80)
  The mean distance of sun from the earth is \[1.5\times {{10}^{8}}Km\] (nearly). The time taken by the light to reach earth from the sun is                                                             [Pb. PET 2003]
  A)
             0.12 min                                  done clear
  B)
             8.33 min done clear
  C)
             12.5 min                                  done clear
  D)
             6.25 min done clear
  View Solution play_arrow

• question_answer81)
  Refractive index of air is 1.0003. The correct thickness of air column which will have one more wavelength of yellow light \[\left( 6000\text{ }{AA} \right)\] than in the same thickness in vacuum is  [RPMT 1995]
  A)
  2 mm                                        done clear
  B)
  2 cm done clear
  C)
  2 m                                            done clear
  D)
  2 km done clear
  View Solution play_arrow

• question_answer82)
  The wavelength of light in air and some other medium are respectively \[{{\lambda }_{a}}\] and \[{{\lambda }_{m}}.\] The refractive index of medium is  [RPMT 2003]
  A)
             \[{{\lambda }_{a}}/{{\lambda }_{m}}\]                          done clear
  B)
             \[{{\lambda }_{m}}/{{\lambda }_{a}}\] done clear
  C)
             \[{{\lambda }_{a}}\times {{\lambda }_{m}}\]             done clear
  D)
             None of these done clear
  View Solution play_arrow

• question_answer83)
  An astronaut in a spaceship see the outer space as                                                          [CPMT 1990, MP PMT 1991; JIPMER 1997]
  A)
             White                                       done clear
  B)
             Black done clear
  C)
             Blue                                          done clear
  D)
             Red done clear
  View Solution play_arrow

• question_answer84)
  Speed of light is maximum in  [CPMT 1990; MP PMT 1994; AFMC 1996]
  A)
             Water                                      done clear
  B)
             Air done clear
  C)
             Glass                                        done clear
  D)
             Diamond done clear
  View Solution play_arrow

• question_answer85)
  Which one of the following statements is correct [KCET 1994]
  A)
             In vacuum, the speed of light depends upon frequency done clear
  B)
             In vacuum, the speed of light does not depend upon frequency done clear
  C)
             In vacuum, the speed of light is independent of frequency and wavelength done clear
  D)
             In vacuum, the speed of light depends upon wavelength done clear
  View Solution play_arrow

• question_answer86)
  If the wavelength of light in vacuum be l, the wavelength in a medium of refractive index n will be         [UPSEAT 2001; MP PET 2001]
  A)
             nl done clear
  B)
             \[\frac{\lambda }{n}\] done clear
  C)
             \[\frac{\lambda }{{{n}^{2}}}\]                                           done clear
  D)
             n2l done clear
  View Solution play_arrow

• question_answer87)
  In vacuum the speed of light depends upon [MP PMT 2001]
  A)
             Frequency done clear
  B)
             Wave length done clear
  C)
             Velocity of the source of light done clear
  D)
             None of these done clear
  View Solution play_arrow

• question_answer88)
  A transparent cube of 15 cm edge contains a small air bubble. Its apparent depth when viewed through one face is 6 cm and when viewed through the opposite face is 4 cm. Then the refractive index of the material of the cube is [CPMT 2004; MP PMT 2005]
  A)
             2.0  done clear
  B)
             2.5  done clear
  C)
             1.6  done clear
  D)
             1.5 done clear
  View Solution play_arrow

• question_answer89)
  A glass slab of thickness 3 cm and refractive index 3/2 is placed on ink mark on a piece of paper. For a person looking at the mark at a distance 5.0 cm above it, the distance of the mark will appear to be     [Kerala PMT 2005]
  A)
             3.0 cm                                      done clear
  B)
             4.0 cm done clear
  C)
             4.5 cm                                      done clear
  D)
             5.0 cm done clear
  View Solution play_arrow

• question_answer90)
  A fish at a depth of 12 cm in water is viewed by an observer on the bank of a lake. To what height the image of the fish is raised.                                                                           [MP PET  2005]
  A)
             9 cm                                          done clear
  B)
             12 cm done clear
  C)
             3.8 cm                                      done clear
  D)
             3 cm done clear
  View Solution play_arrow