Video Solutions for GATE 1997 ECE : One Mark Questions ( Electron Devices )

1. For a MOS capacitor fabricated on a P-type semiconductor, 

    strong inversion occurs when

        (a) Surface potential is equal to Fermi Potential

        (b) Surface Potential is zero

        (c) Surface Potential is negative and equal to Fermi potential  

              in magnitude

        (d) Surface potential is positive and equal to twice the Fermi 

              potential

2. In a common emitter BJT amplifier, the maximum usable supply 

    voltage is limited by

  (a)  Avalanche breakdown of Base Emitter junction

  (b)  Collector Base breakdown voltage with emitter open (BV_CBO)

  (c)  Collector emitter breakdown voltage with base open (BV_CEO)

  (d)  Zener breakdown voltage of the Emitter Base junction

3. In the circuit shown, the current  flowing through the ideal diode 

    ( zero cut in voltage and forward resistance) equal to 

4. The intrinsic carrier density at 300^oK is 1.5x10¹⁰ /cm³ for

    silicon. For n-type silicon doped to 2.25x10¹⁵ atoms/cm³,

    the equilibrium electron and hole densities are

 

  

5. The gate delay of an NMOS inverter is dominated by charge 

     time rather than discharge time because