Question

A N-P-N transistor is connected in common emitter configuration in which collector supply is $8volt$ and the voltage drop across the load resistor of $800ohm$ connected to the collector circuit is $0.8volt.$ If current amplification factor $\alpha$ is $\frac{25}{26}$ and the input resistance of the transistor is $200ohm$ then the collector emitter voltage, base current, the voltage and power gain are

• A. $3.5V,2\times {10}^{-5}A$ and $A_V=50V,A_P=6500$
• B. $7.5V,4\times {10}^{-5}A$ and $A_V=100V,A_P=2500$
• C. $4.5V,3\times {10}^{-5}A$ and $A_V=50V,A_P=6500$
• D. $5.6V,3\times {10}^{-5}A$ and $A_V=60V,A_P=7500$

Answer 1

The correct option is A $3.5V,2\times {10}^{-5}A$ and $A_V=50V,A_P=6500$

$V_{CE}=8$

$R=800$

$V_C=0.8$

$\alpha =0.96$

$I_b=?$

$B=\left(\frac{\alpha }{1-\alpha }\right)=\frac{0.96}{1-0.96}=24$

$I_C=\frac{V}{R}=\left(\frac{0.8}{800}\right)=\frac{5}{8}\times {10}^{-3}$

$=\frac{5}{8}\times {10}^{-3}$

$I_b=26\mu A$

or $2.6\times {10}^{-5}$