Video Solutions for GATE 1995 ECE : One Mark Questions ( Electron Devices )

1. The drift velocity of electrons, in silicon 

 

2. The diffusion potential across a PN junction

 

3. The breakdown voltage of a transistor with its base open

     is BV_CEO , that with emitter open is BV_CBO then 

(a)  BV_CEO  =  BV_CBO          (b)  BV_CEO  >  BV_CBO     

(c)  BV_CEO  < BV_CBO          (d)  BV_CEO  not related to   BV_CBO

 

 

4. In a P-type silicon sample, the hole concentration

    is 2.25x10¹⁵ /cm³. If the intrinsic carrier concentration

    is 1.5x10¹⁰ /cm³, the electron concentration is 

              (a)  Zero                               (b)  10¹⁰ /cm³     

  

              (c)  10⁵ /cm³                         (d)  1.5x10¹⁰ /cm³

 

 

5. A zener diode works on the principle of

 

6. A BJT is said to be operating in the saturation region if

        (a)  Both the junctions are reverse biased

(b)  Base emitter junction is reverse biased and base collector 

       junction is forward biased

(c)  Base emitter junction is forward biased and base collector 

       junction reverse biased

(d)  Both the junctions are forward biased

 

7. The depletion capacitance, C_J, of an abrupt PN junction with 

    constant doping on either side varies with reverse bias, V_R as

 

8. The Ebers-Moll model  is applicable to