Q136 / 180 · AIIMS 2012 · Physics
For a common-emitter transistor, input current is $5 \mu \mathrm{A}, \beta=100$ circuit is operated at load resistance of $10 \mathrm{k} \Omega$, then voltage across collector emitter will be
- Correct answerA$5 \mathrm{~V}$
- B$10 \mathrm{~V}$
- C$12.5 \mathrm{~V}$
- D$7.5 \mathrm{~V}$
Solution
Here, $I_B=5 \mu \mathrm{A}=5 \times 10^{-6} \mathrm{~A}$
$\beta=100$
$R_L=10 \mathrm{k} \Omega=10 \times 10^3 \Omega$
As $\beta=\frac{I_C}{I_B}$
or $I_C=(100)\left(5 \times 10^{-6} \mathrm{~A}\right)=5 \times 10^{-4} \mathrm{~A}$
The voltage across collector emitter is
$V_{C E}=R_L I_C=\left(10 \times 10^3 \Omega\right)\left(5 \times 10^{-4} \mathrm{~A}\right)=5 \mathrm{~V}$
Hence, the correct answer is option: 'A'.