JEE PYQ: Semiconductors Question 45
Question 45 - 2019 (12 Jan 2019 Shift 1)
In the figure, given that $V_{BB}$ supply can vary from 0 to 5.0 V, $V_{CC} = 5$ V, $\beta_{dc} = 200$, $R_B = 100\ \text{k}\Omega$, $R_C = 1\ \text{k}\Omega$ and $V_{BE} = 1.0$ V. The minimum base current and the input voltage at which the transistor will go to saturation, will be, respectively:
(1) $25\ \mu$A and 3.5 V
(2) $20\ \mu$A and 3.5 V
(3) $25\ \mu$A and 2.8 V
(4) $20\ \mu$A and 2.8 V
Show Answer
Answer: (1)
Solution
At saturation $I_C = V_{CC}/R_C = 5 \times 10^{-3}$ A. $I_B = I_C/\beta = 25\ \mu$A. $V_{BB} = I_B R_B + V_{BE} = 2.5 + 1 = 3.5$ V.
BETA
