Question

For a constant collector-emitter voltage of 8V, the collector current of a transistor reached to the value of 6 mA from 4 mA, whereas base current changed from 20 µA to 25 µA value. If transistor is in active state, small signal current gain (current amplification factor) will be ______.

पर्याय

• 240

• 400

• 0.0025

• 200

Answer 1

For a constant collector-emitter voltage of 8V, the collector current of a transistor reached to the value of 6 mA from 4 mA, whereas base current changed from 20 µA to 25 µA value. If transistor is in active state, small signal current gain (current amplification factor) will be 400.

Explanation:

Collector-emitter voltage, V_CE = 2V

Initial collector current, I_C = 4 mA

Final collector current, I_C = 6 mA

Initial base current, I_B = 20 µA

Final base current, I_B = 25 µA

Current gain β_av = `("I"_"C"-"I"_"C")/("I"_"B"-"I"_"B") = (2"mA")/(5mu"A")` 

⇒ β_av = `2/5xx10^3`

= `2000/5`

= 400