111. A sound wave having wavelength λ forms stationary waves after reflection from a surface. The distance between two consecutive nodes is

1. 1. λ

   
   
   

   2. λ / 2

   
   
   

   3. λ / 4

   
   
   

   4. λ / 8

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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112. The patient is asked to drink barium sulphate (BaSO₄) for examining the stomach by X - rays because X - rays are

1. 1. Reflected by heavy atoms

   
   
   

   2. Refracted by heavy atoms

   
   
   

   3. Less absorbed by heavy atoms

   
   
   

   4. More absorbed by heavy atoms

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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113. Consider the following parts of spectra
     1. Visible
     2. Infrared
     3. Ultraviolet
     4. Microwave
     Which one of the following is the correct sequence in which their wavelengths increase?
     

1. 1. 4-3-1-2

   
   
   

   2. 4-1-2-3

   
   
   

   3. 3-2-1-4

   
   
   

   4. 3-1-2-4

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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114. Which among the following is the necessary condition for simple harmonic motion?

1. 1. Constant period

   
   
   

   2. Constant acceleration

   
   
   

   3. Acceleration is proportional to the displacement form mean position and is always directed towards it

   
   
   

   4. Displacement and torque are proportional

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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115. X -rays are not used for radar purpose because

1. 1. They are not reflected by the target

   
   
   

   2. They are completely absorbed by air

   
   
   

   3. They are not electromagnetic wave

   
   
   

   4. None of the above

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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