71. The material used in solar cells contains

1. 1. Cs

   
   
   

   2. Si

   
   
   

   3. Sn

   
   
   

   4. Ti

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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72. The composition of common glass is

1. 1. Na₂O, CaO,6SiO₂

   
   
   

   2. Na₂O.AI₂O₃.SiO₂

   
   
   

   3. CaO.Al₂O₃.SiO₂

   
   
   

   4. FeSO₄.Al₂(SO₄)₃.24H₂O

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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73. The superior type of Laboratory apparatus are made of

1. 1. Sodalime glass

   
   
   

   2. Hard glass

   
   
   

   3. Fline glass

   
   
   

   4. Pyrex glass

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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74. Germenium is an example of

1. 1. An intrinsic semiconductor

   
   
   

   2. An n-type semiconductor

   
   
   

   3. A p-type semiconductor

   
   
   

   4. An insulator

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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75. Which is the catalyst used in manufacture of sulphuric acid by lead chamber process ?

1. 1. Fe

   
   
   

   2. Ni

   
   
   

   3. Pb

   
   
   

   4. Oxides of nitrogen

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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