A transistor is operated in common emitter configuration at V_{C} = 2 V such that a change in the base current from 100 μA to 300 μA produces a change in the collector current from 10 mA to 20 mA. The current gain is

Option 2 : 50

CT 1: Network Theory 1

12350

10 Questions
10 Marks
10 Mins

__CONCEPT:__

Transistor: A semiconductor device used to amplify or switch electronic signals and electrical power is called a transistor.

- It is made of semiconductor material with at least three terminals for connection to an external circuit.

- In Common emitter configuration (CE) emitter is the common terminal.

- In common emitter configuration, the emitter is common to both base and collector.
- The emitter-base junction is always forward bias as a positive terminal of the battery is connected to the p-side of the transistor and the negative terminal of the battery is connected to the n-side of the transistor.
- The current amplification factor is the ratio of change in the collector current (ΔIC) to change in the base current (ΔIb). The equation is given by

\(β =\frac{ I_{c}}{I_{B}}\)

Where β = Current amplification factor IC = Collector current IB= Base current

__CALCULATION__:

Given - VC = 2 V, I_{B1} = 100μA, I_{B2} = 300μA, Ic1 = 10 mA, and Ic2 = 20 mA,

The change in base current (ΔI_{B}) = I_{B2} - I_{B1} = 300μA - 100μA = 200μA

The change in collector current (ΔIC) = Ic2 - Ic1 = 20 - 10 = 10 mA

- The current amplification factor is the ratio of change in the collector current (ΔIC) to change in the base current (ΔIb).The equation is given by

\(\Rightarrow β =\frac{\Delta I_{c}}{\Delta I_{B}}\)

Substituting the given values in the above equation, we get

\(\Rightarrow β =\frac{\Delta I_{c}}{\Delta I_{B}} =\frac{10 mA}{200 \mu A} =50\)

- The current amplification factor is 50.