146. Stationary waves are so called because in them

1. 1. The particles of the medium are not disturbed at all

   
   
   

   2. The particles of the medium do not execute SHM

   
   
   

   3. These occurs no flow of energy

   
   
   

   4. The interference effect can't be observed

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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147. Some common mediums in which speed of sound of sound?
     1. Air
     2. Steel
     3. Copper
     4. Water
     What is the correct increasing order of the speed of sound ?

1. 1. 1 < 4 < 2 < 3

   
   
   

   2. 4 < 1 < 2 < 3

   
   
   

   3. 1 < 4 < 3 < 2

   
   
   

   4. 4 < 1 < 3 < 2

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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148. Which one of the following is the correct sequence of wavelengths of radiations ?

1. 1. UV > Green > IR > Hard X - rays

   
   
   

   2. IR > Green > UV > Hard X - rays

   
   
   

   3. UV > Hard > IR > Green

   
   
   

   4. IR > Hard X - rays > Green > UV

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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149. An echo will be heard if the minimum distance between the source of sound and obstacle is

1. 1. 1 m

   
   
   

   2. 10 m

   
   
   

   3. 15 m

   
   
   

   4. 17 m

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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150. The audible frequency range of a human ear is

1. 1. 20 hertz to 200 hertz

   
   
   

   2. 2 hertz to 20 hertz

   
   
   

   3. 200 hertz to 2000 hertz

   
   
   

   4. 20 hertz to 20000 hertz

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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