466. In a p-type semiconductor—

1. 1. The hole concentration is less the electron concentration

   
   
   

   2. Electrons are the majority carriers

   
   
   

   3. At room temperature the hole concentration equals the acceptor concentration

   
   
   

   4. Electron density does not change with temperature

   
   
   

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1. View Hint View Answer Discuss in Forum

   We know that charge neutrality equation n + N_A = P + N_D For p-type semiconductor p >> n
   ∴ P = N_A i.e. acceptor concentration.

   Correct Option: C

   We know that charge neutrality equation n + N_A = P + N_D For p-type semiconductor p >> n
   ∴ P = N_A i.e. acceptor concentration.

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467. For transistor action—
     

1. 1. The collector must be more heavily doped than the emitter region

   
   
   

   2. The collector-base junction must be forward-biased

   
   
   

   3. The base region must be very narrow

   
   
   

   4. The base region must be n-type material

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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468. The symbol I_CBO signifies the current that flows when some dc voltage is applied—

1. 1. In the reverse direction to the collector junction with the emitter open-circuited

   
   
   

   2. In the forward direction to the collector junction with the emitter open-circuited

   
   
   

   3. In the reverse direction to the emitter junction with the collector open-circuited

   
   
   

   4. In the forward direction to the emitter junction with the collector open-circuited

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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469. The current I_CBO—

1. 1. Is generally greater in silicon than in germanium transistors

   
   
   

   2. Depends largely on the emitter-base junction bias

   
   
   

   3. Depends largely on the emitter doping

   
   
   

   4. Increases with an increase in temperature
      

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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470. The main current crossing the collection junction in a normally biased NPN transistor is—
     

1. 1. A diffusion current

   
   
   

   2. A drift current

   
   
   

   3. A hole current

   
   
   

   4. Equal to the base current

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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