Question

Find the value of resistance R when VCE=2V,VBE=0.7V,beta=50

Answer 1

Given that,

The value of $V_{CE}=2\ V$

The value of  $V_{BE}=0.7\ V$

The value of $\beta=50$

Suppose, Base resistance is 2kΩ,  $V_{BB}=3$ and $V_{CC}=9$

We need to calculate the collector current

Using formula of voltage

$V_{BE}=V_{CC}-I_{C}\times R_{C}$

$I_{C}=\dfrac{V_{BE}-V_{CC}}{-R_{C}}$

Put the value into the formula

$I_{C}=-\dfrac{2-9}{2\times10^{3}}$

$I_{C}=3.5\times10^{-3}\ A$

We need to calculate the base current

Using formula of $\beta$

$\beta=\dfrac{I_{C}}{I_{B}}$

$I_{B}=\dfrac{I_{C}}{\beta}$

Put the value into the formula

$I_{B}=\dfrac{3.5\times10^{-3}}{50}$

$I_{B}=7.0\times10^{-5}\ A$

We need to calculate the Base resistance

Using formula of voltage base emitter

$V_{BE}=-I_{B}R_{B}+V_{BB}$

$R_{B}=-\dfrac{V_{BE}-V_{BB}}{I_{B}}$

Put the value into the formula

$R_{B}=-\dfrac{0.7-3}{7.0\times10^{-5}}$

$R_{B}=32.8\times10^{3}\ \Omega$

$R_{B}=32.8\ k\Omega$

Hence, The Base resistance is 32.8 kΩ.

Learn more :

Topic : transistor

https://brainly.in/question/8735394