# In a transistor if #I_c/I_e=alpha# and #I_c/I_b=beta#, if #alpha# varies between #(20)/(21)# and #(100)/(101)#, then the value of #beta# lied between?

##### 1 Answer

#### Answer:

#### Explanation:

Representative circuit in Common emitter amplifier configuration is given below

Given is the ratio of

And the ratio of

From above expressions we have

In this configuration, the current flowing out of the transistor must be equal to the currents flowing into the transistor. As such we have

#I_e = I_c + I_b# .....(2)

To have a combined the expression for

#=>beta=alpha/(1-alpha)#

For

Again for

.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-

Note: value of

and typically,