A common emitter amplifier circuit is built using npn transistor, if DC current gain is 250,Rc= 1KΩ and VCC=10V . Calculate minimum base current for VCE to reach the saturation.

Question

A common emitter amplifier circuit is built using npn transistor, if DC current gain is 250,Rc= 1KΩ and VCC=10V . Calculate minimum base current for VCE to reach the saturation. <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/p-fuy7j4gtveopligc.jpg" /> (A) 100μA (B) 7μA (C) 40μA (D) 10μA

Tardigrade Admin · Accepted Answer

Using Ohm's law, ic=(10 V/1 k Ω)=10mA In common emitter configuration, current gain β β =(ic/ib)=250 ⇒ ib=(ic/β )=(10 mA/250)=40Î¼A

Q. A common emitter amplifier circuit is built using $n p n$ transistor, if $D C$ current gain is $250, R_{c} =$ $1 K Ω$ and $V_{CC} = 10 V$ . Calculate minimum base current for $V_{CE}$ to reach the saturation.

$100 μ A$

$7 μ A$

$40 μ A$

$10 μ A$

Using Ohm's law,
$i_{c} = \frac{10 V}{1 k Ω} = 10 m A$
In common emitter configuration, current gain $β$
$β = \frac{i _{c}}{i _{b}} = 250$
$\Rightarrow i_{b} = \frac{i _{c}}{β} = \frac{10 m A}{250} = 40 μ A$

Q. A common emitter amplifier circuit is built using npn transistor, if DC current gain is 250,Rc​= 1KΩ and VCC​=10V . Calculate minimum base current for VCE​ to reach the saturation.

100μA

7μA

40μA

10μA