waecE-LEARNING
Electronics Paper 2, Nov/Dec. 2011  
Questions: 1 2 3 4 5 6 7 8 9 10 Main
General Comments
Weakness/Remedies
Strength















Question 3

(a)      Define the following static parameters of a transistor connected in common emitter configuration:
          (i)    current gain;
          (ii)   output impedance.
(b)     Draw and label the output characteristics of the common emitter transistor configuration.
(c)      A transistor has a base current, Ib, of 50 mA and a collector current, Ic, of 2 mA. If a voltage, VCE,           of 7.5 V is applied, calculate the
          (i)      current gain,

          (ii)      output impedance.
_____________________________________________________________________________________________________
OBSERVATION

The expected answers were:
(a)      (i)      Current Gain
          (ii)      Output impedance Zo =
(b)


(b)     Assumption of CE configuration

  1.  =  = 0.04
  2.  =  =  = 3.75 kΩ

The question was on Amplifiers. The question was attempted by many candidates. The performance was average.The expected answers were:
(a)      (i)      Current Gain
          (ii)      Output impedance Zo =
(b)
(b)     Assumption of CE configuration

  1.  =  = 0.04
  2.  =  =  = 3.75 kΩ

The question was on Amplifiers. The question was attempted by many candidates. The performance was average.

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