Question

In an n-p-n transistor, 1010 electrons enter the emitter in 10–6 s. 2% of the electrons are lost in the base. Calculate the current transfer ratio and the current amplification factor. Charge on electron is .

Solution

Correct option is

0.98, 49

 

The current is rate of flow of change (q/t). Since 1010 electrons enter the emitter in 10–6 s, the emitter-current is

        

            

            = 1.6 mA

Similarly, the base-current is 

       

           

           = 0.032 mA.

In transistor, the emitter current  is the sum of the base current  and the collector current 

  

            = 1.6 mA – 0.032 mA     

            = 1.568 mA.

The current transfer ratio is 

        

            = 0.98. 

The current amplification factor is 

          

            = 49.

SIMILAR QUESTIONS

Q1

In a p-n-p transistor with normal bias:

Q2

The base-current of a transistor is  and the collector-current is 2.05 mA. A change of  in the base-current produces a change of 0.65 mA in the collector current. Find .  

Q3

The current-gain of a transistor in a common-base arrangement is 0.98. Find the change in collector-current corresponding to a change of 5.0 mA in emitter-current. What would be the change in the base-current?

Q4

In a common-base amplifier the load-resistance of the output circuit is  and the resistance of the input circuit is . If current-gain be 0.95, calculate the voltage-gain and the power gain.

Q5

In input and output resistances in a common-base amplifier circuit are  respectively. If the current-gain  is 0.98, then find the voltage gain. If the emitter-current is 2 mA, then find the collector-current and the base-current. 

Q6

The a-c current gain  of a transistor is 150. What will be the change in the collector-current for a change of  in its base-current? What will be the change in the emitter-current? 

Q7

Find the voltage gain and power gain in a transistor amplifier in common-emitter configuration when  and the input and the output ersistance are .

Q8

The input resistance of a silicon transistor is . Its base-current is changed by  which results in a change of 2 mA in the collector-current. The transistor is used as a common-emitter amplifier with a load resistance of . What is the voltage gain of the amplifier? Also calculate the transconductance of the transistor.

Q9

A change of 0.2 mA in base-current causes a change of 5 mA in the collector-current for a common-emitter amplifier. Find the a-c current gain of the transistor.   

Q10

A transistor is connected in common-emitter configuration. The collector-supply is 8 V and the voltage drop across a resistor of  in the collector circuit is 0.5 V. If the current-gain factor  is 0.96, find the base-current.