Question

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.   

Solution

Correct option is

25

 

By definition, the alternating-current gain  is give by 

       

                         

                          = 25.

SIMILAR QUESTIONS

Q1

The diffusion current in a p-n junction is 

Q2

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

Q3

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 .  

Q4

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?

Q5

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.

Q6

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. 

Q7

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? 

Q8

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

Q9

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.

Q10

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 .