131. Which of the following statements are true regarding heat?
     1. Heat is a form of energy
     2. Heat can be reflected by mirror
     3. Heat is an electromagnetic radiation
     4. Heat can not pass through vacuum
     Select the correct answer from the codes given below
     Codes :

1. 1. 1, 2 and 3

   
   
   

   2. 2, 3 and 4

   
   
   

   3. 1, 2 and 4

   
   
   

   4. 1, 3 and 4

   
   
   

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   N/A

   Correct Option: D

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132. When an ideal gas under goes an isothermal expansion, the pressure of the gas in the enclosure falls. This is due to

1. 1. Decreased in the change of momentum per collision

   
   
   

   2. Decrease in the frequency of collision

   
   
   

   3. Decrease in the frequency of collision and the change of momentum per collision

   
   
   

   4. Decrease in neither the frequency of collision nor the change of momentum per collision

   
   
   

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   N/A

   Correct Option: B

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133. Which of the following statement (s) is (are) true about thermal radiations?
     (i) Thermal radiation are electromagnetic waves
     (ii) All bodies emit thermal radiations at all temperature
     (iii) Thermal radiations are reflected from mirror
     (iv) Thermal radiations of all wavelengths travel in free space with same velocity
     Choose the correct answer

1. 1. (i), (ii) and (iii)

   
   
   

   2. (ii), (iii) and (iv)

   
   
   

   3. (iii) and (iv)

   
   
   

   4. All of them

   
   
   

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   N/A

   Correct Option: D

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134. In a pressure cooker the cooking is fast because

1. 1. The boiling point of water is raised by the increased pressure inside the cooker

   
   
   

   2. The boiling point of water is lowered by the increased pressure

   
   
   

   3. More steam is available to cook the food at 1000°C

   
   
   

   4. None of the above

   
   
   

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   N/A

   Correct Option: A

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135. A cooking pot should have

1. 1. High specific heat and low conductivity

   
   
   

   2. High specific heat and high conductivity

   
   
   

   3. Low specific heat and low conductivity

   
   
   

   4. Low specific heat and high conductivity

   
   
   

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1. View Hint View Answer Discuss in Forum

   N/A

   Correct Option: B

   N/A

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