Draw a  circuit diag of a common emmitter  amplifier using  n-p-n transistor. Show input and output voltages graphically.The current gain for common emitter is 59.If the emitter current is 6m A  find (1) base current  (2) collector current 

Hi,

Here is the circuit diagram of an NPN transistor in common emitter mode as an amplifier.

The following graph shows the load line of the transistor and the input and output wave form of the signal.

In CE mode the current gain is given by,

β = (I_c)/(I_b) = 59  ……………………………….(1)

Since, I_e = I_b + I_c

=> 6 × 10^-3 = I_b + I_c  …………………………….(2)

Solving (1) and (2) we get,

Base current, I_b = 0.0001 A = .1 mA

Collector current, I_c = .0059 A = 5.9 mA