41. When X -rays are produced, then

1. 1. Heat is produced on the target

   
   
   

   2. Heat is observed by the target

   
   
   

   3. Temperature of the target is being constant

   
   
   

   4. A luminous light is to be seen on the target

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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42. Consider the following statements
    1. Light of longer wavelength is scattered much more than the light of shorter wavelength.
    2. The speed of visible light in water is 0.95 times the speed in vacuum.
    3. Radio waves are produced by rapidly oscillating electrical currents.
    4. To detect the overspending vehicles, police use the Doppler effect of reflected short radio waves
    Which of these statements are correct?

1. 1. 1 and 2

   
   
   

   2. 1 and 3

   
   
   

   3. 2 and 4

   
   
   

   4. 3 and 4

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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43. Penetrating power of X-rays does not depend on

1. 1. Wavelength

   
   
   

   2. Energy

   
   
   

   3. Potential difference

   
   
   

   4. Current in the filament

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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44. 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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45. If T is the reverberation time of an auditorium of volume V then

1. 1. T ∝ V

   
   
   

   2. T ∝ 1 / V

   
   
   

   3. T ∝ V²

   
   
   

   4. T ∝ 1 / V²

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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