Question

When the base current in a transistor is changed from 30µA to 80µA, the collector current is changed from 1.0 mA to 3.5 mA. Find the current gain β.

Answer 1

Current Gain is 50 A

Explanation:

$\delta I_b = 80\mu A - 30\mu A$

= $50\mu A = 50 \times 10^-^6 A$

$\delta I_c = 3.5 mA - 1mA = -2.5 mA$

= $2.5 \times 10^-^3 A$

$\beta = (\frac {\delta I_c}{\delta I_b})V_c_e = Constant$

Hence,  

$\frac {2.5 \times 10^-^3}{50 \times 10^-^6}$

= $\frac {2500}{50}$

=$50$

Current Gain in the Circuit = 50 A