In common base circuit of a transistor, current amplification factor is 0.95. Calculate the emitter current if base current is 0.2 mA

Question

In common base circuit of a transistor, current amplification factor is 0.95. Calculate the emitter current if base current is 0.2 mA (A) 2 mA (B) 4 mA (C) 6 mA (D) 8 mA

Tardigrade Admin · Accepted Answer

Given, α=0.95, Ib=0.2 mA As α=(Ic/Ie)=(Ie-Ib/Ie)=1-(Ib/Ie) ⇒ (Ib/Ie)=1-α=1-0.95 ⇒ (Ib/Ie)=0.05 ⇒ (0.2/0.05) mA =Ie ⇒ Ie=4 mA

Q. In common base circuit of a transistor, current amplification factor is $0.95$ . Calculate the emitter current if base current is $0.2 m A$

$2 m A$

$4 m A$

$6 m A$

$8 m A$

Given, $α = 0.95, I_{b} = 0.2 m A$
As $α = \frac{I _{c}}{I _{e}} = \frac{I _{e} - I _{b}}{I _{e}} = 1 - \frac{I _{b}}{I _{e}}$
$\Rightarrow \frac{I _{b}}{I _{e}} = 1 - α = 1 - 0.95$
$\Rightarrow \frac{I _{b}}{I _{e}} = 0.05 \Rightarrow \frac{0.2}{0.05} m A = I_{e}$
$\Rightarrow I_{e} = 4 m A$

Q. In common base circuit of a transistor, current amplification factor is 0.95. Calculate the emitter current if base current is 0.2mA

2mA

4mA

6mA

8mA