Solved papers for NEET Physics EM Waves NEET PYQ-EM Waves

done NEET PYQ-EM Waves Total Questions - 23

• question_answer1) Ozone layer blocks the radiations of wave length:                                                    [AIPMT 1999]
  A)
   less than \[3\times {{10}^{-7}}\,m\]     
  done clear
  B)
   equal to \[3\times {{10}^{-7}}\,m\]
  done clear
  C)
   more than \[3\times {{10}^{-7}}\,m\]   
  done clear
  D)
   all of the above
  done clear
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• question_answer2) The wavelength of light of frequency 100 Hz is:                                                                  [AIPMT 1999]
  A)
   \[2\times {{10}^{6}}m\]         
  done clear
  B)
        3\[3\times {{10}^{6}}m\]
  done clear
  C)
   \[4\times {{10}^{6}}m\]
  done clear
  D)
                    \[5\times {{10}^{6}}m\]
  done clear
  View Answer play_arrow

• question_answer3) The electromagnetic radiations are caused by:                                                         [AIPMT 1999]
  A)
   a stationary charge
  done clear
  B)
                                uniformly moving charges
  done clear
  C)
        accelerated charges
  done clear
  D)
                                all of the above
  done clear
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• question_answer4) The frequency of \[\gamma -rays,\] X-rays and ultraviolet rays are a, b and c respectively. Then:
  A)
   \[a>b>c\]        
  done clear
  B)
        \[a<b<c\]
  done clear
  C)
   \[a=b=c\]
  done clear
  D)
        \[a>c>b\]
  done clear
  View Answer play_arrow

• question_answer5) Ozone layer in atmosphere is useful, because it:                                                                  [AIPMT 2001]
  A)
         stops ultraviolet radiation
  done clear
  B)
                    absorbs polluent gases
  done clear
  C)
   stops green house effect             
  done clear
  D)
        stops increase in temperature of atmosphere
  done clear
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• question_answer6) What is the cause of "Greenhouse effect"?                                                                           [AIPMT 2002]
  A)
         Infrared rays     
  done clear
  B)
        Ultraviolet rays
  done clear
  C)
        X-rays               
  done clear
  D)
        Radio-waves
  done clear
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• question_answer7) The velocity of electromagnetic wave is along the direction of:                                [AIPMT 2002]
  A)
   \[\vec{B}\times \vec{E}\]
  done clear
  B)
                    \[\vec{E}\times \vec{B}\]
  done clear
  C)
   \[\vec{E}\]       
  done clear
  D)
                    \[\vec{B}\]
  done clear
  View Answer play_arrow

• question_answer8) Which of the following has minimum wavelength?                                                               [AIPMT 2002]
  A)
   X-rays   
  done clear
  B)
                    Ultraviolet rays
  done clear
  C)
   \[\gamma \]-rays   
  done clear
  D)
        Cosmic rays
  done clear
  View Answer play_arrow

• question_answer9) Which of the following rays are not electromagnetic waves?                                             [AIPMT 2003]
  A)
   \[\beta \]-rays
  done clear
  B)
                    Heat rays         
  done clear
  C)
   X-rays 
  done clear
  D)
                    \[\gamma \]-rays
  done clear
  View Answer play_arrow

• question_answer10) We consider the radiation emitted by the human body. Which of the following statements is true?          [AIPMT 2003]
  A)
   The radiation is emitted during the summers and absorbed during the winters
  done clear
  B)
        The radiation emitted lies in the ultraviolet region and hence is not visible
  done clear
  C)
        The radiation emitted is in the infra-red region
  done clear
  D)
        The radiation is emitted only during the day
  done clear
  View Answer play_arrow

• question_answer11) If \[{{\lambda }_{v}},\,{{\lambda }_{x}}\,\] and \[{{\lambda }_{m}}\] represent the wavelengths of visible light, X-rays and microwaves respectively, then:                                                                              [AIPMT (S) 2005]
  A)
   \[{{\lambda }_{m}}>{{\lambda }_{x}}>{{\lambda }_{v}}\]    
  done clear
  B)
        \[{{\lambda }_{v}}>{{\lambda }_{m}}>{{\lambda }_{x}}\]
  done clear
  C)
   \[{{\lambda }_{m}}>{{\lambda }_{v}}>{{\lambda }_{x}}\]
  done clear
  D)
        \[{{\lambda }_{v}}>{{\lambda }_{x}}>{{\lambda }_{m}}\]
  done clear
  View Answer play_arrow

• question_answer12) The electric and magnetic field of an electromagnetic wave are:                                   [AIPMT (S) 2007]
  A)
   in phase and parallel to each other
  done clear
  B)
        in opposite phase and perpendicular to each other
  done clear
  C)
        in opposite phase and parallel to each other
  done clear
  D)
    in phase and perpendicular to each other
  done clear
  View Answer play_arrow

• question_answer13) The velocity of electromagnetic radiation in a medium of permittivity \[{{\varepsilon }_{0}}\] and permeability \[{{\mu }_{0}}\] is given by                                                                                             [AIPMPT (S) 2008]
  A)
   \[\sqrt{\frac{{{\varepsilon }_{0}}}{{{\mu }_{0}}}}\]
  done clear
  B)
       \[\sqrt{{{\mu }_{0}}{{\varepsilon }_{0}}}\]
  done clear
  C)
   \[\frac{1}{\sqrt{{{\mu }_{0}}{{\varepsilon }_{0}}}}\]   
  done clear
  D)
        \[\sqrt{\frac{{{\mu }_{0}}}{{{\varepsilon }_{0}}}}\]
  done clear
  View Answer play_arrow

• question_answer14) 

  The electric field of an electromagnetic wave in free space is given by

  \[\overset{\to }{\mathop{\mathbf{E}}}\,=10\cos ({{10}^{7}}t+kx)\mathbf{\hat{j}}v/m,\] where t and x are in seconds and metres respectively. It can be inferred that                                                                        [AIPMT (M) 2010]

  (1) The wavelength \[\lambda \] is 188.4 m.

  (2) The wave number k is 0.33 rad/m.

  (3) The wave amplitude is 10 V/m.

  (4) The wave is propagating along \[+x\] direction Which one of the following pairs of statements is correct?

  A)
   (3) and (4)       
  done clear
  B)
   (1) and (2)       
  done clear
  C)
   (2) and (3) 
  done clear
  D)
   (1) and (3)
  done clear
  View Answer play_arrow

• question_answer15) The decreasing order of wavelength of infrared, microwave, ultraviolet and gamma rays is        [AIPMT (S) 2011]
  A)
   gamma   rays,   ultraviolet,   infrared, microwaves
  done clear
  B)
  (b microwaves,   gamma   rays,   infrared, ultraviolet
  done clear
  C)
   infrared, microwave, ultraviolet, gamma rays
  done clear
  D)
   microwave infrared, ultraviolet, gamma rays
  done clear
  View Answer play_arrow

• question_answer16)  The dimensions of \[{{({{\mu }_{0}}{{\varepsilon }_{0}})}^{-1/2}}\] are                        [AIPMT (M) 2012]
  A)
   \[[{{L}^{1/2}}T{{-}^{1/2}}]\]           
  done clear
  B)
        \[[{{L}^{-1}}T]\]        
  done clear
  C)
   \[[L{{T}^{-1}}]\]        
  done clear
  D)
        \[[{{L}^{1/2}}{{T}^{1/2}}]\]
  done clear
  View Answer play_arrow

• question_answer17) The ratio of amplitude of magnetic field to the amplitude of electric field for an electromagnetic  wave  propagating  in vacuum is equal to                                                                                                          [AIPMT (M) 2012]
  A)
   the speed of light in vacuum
  done clear
  B)
   reciprocal of speed of light in vacuum
  done clear
  C)
   the ratio of magnetic permeability to the electric susceptibility of vacuum
  done clear
  D)
   unity
  done clear
  View Answer play_arrow

• question_answer18) The   condition   under which   a microwave oven heats up a food item containing water molecules most efficiently is                                                                                                                                          [NEET 2013]
  A)
   the frequency of the microwave must match the resonant frequency of the water molecules
  done clear
  B)
   the frequency of the microwave has no relation with natural frequency of water molecules
  done clear
  C)
   microwave are heat waves, so always produce heating
  done clear
  D)
   infrared waves produce heating in a microwave oven
  done clear
  View Answer play_arrow

• question_answer19) The energy of the EM waves is of the order of \[15\text{ }keV\]. To which part of the spectrum does it belong?                                                                                                                                                   [NEET (Re) 2015]
  A)
   X-rays             
  done clear
  B)
    Infrared rays
  done clear
  C)
   Ultravioiet rays   
  done clear
  D)
     \[\gamma \]-rays
  done clear
  View Answer play_arrow

• question_answer20) Out of the following options which one can be   used to produce a propagating electromagnetic wave?   [NEET - 2016]
  A)
   A charge moving at constant velocity
  done clear
  B)
   A stationary charge
  done clear
  C)
   A chargeless particle
  done clear
  D)
   An accelerating charge
  done clear
  View Answer play_arrow

• question_answer21) In an electromagnetic wave in free space the root mean square value of the electric field is \[{{E}_{rms}}=6\,V/m\]. The peak value of the magnetic field is                                                                                            [NEET-2017]
  A)
   \[4.23\times {{10}^{-8}}T\]                 
  done clear
  B)
   \[1.41\times {{10}^{-8}}T\]
  done clear
  C)
   \[2.83\times {{10}^{-8}}T\]
  done clear
  D)
   \[0.70\times {{10}^{-8}}T\]
  done clear
  View Answer play_arrow

• question_answer22) An em wave is propagating in a medium with a velocity \[\overrightarrow{\text{v}}=\text{v}\widehat{\text{i}}\]. The instantaneous oscillating electric field of this em wave is along \[\text{+y}\] axis. Then the direction of oscillating magnetic field of the em wave will be along                                                                                [NEET - 2018]
  A)
   -y direction       
  done clear
  B)
        +z direction
  done clear
  C)
    -z direction                  
  done clear
  D)
   -x direction
  done clear
  View Answer play_arrow

• question_answer23) The ratio of contributions made by the electric field and magnetic field components to the intensity of an electromagnetic wave is: (c = speed of electromagnetic waves)                                            [NEET 2020]
  A)
   \[1:1\]  
  done clear
  B)
                    \[1:c\]
  done clear
  C)
   \[1:{{c}^{2}}\]
  done clear
  D)
                    \[c:1\]
  done clear
  View Answer play_arrow