A common emitter amplifier circuit, built using an npn transistor, is shown in the figure. Its dc current gain is $250, \,R_C = 1k\Omega$ and $V_{CC} = 10 V$.
What is the minimum base current for $V_{CE}$ to reach saturation ?
- $100 \,\mu A$
- $7 \,\mu A$
- $40 \,\mu A$
- $10 \,\mu A$
The Correct Option is C
Solution and Explanation
$\Rightarrow i_{C} = \frac{10V}{1000\Omega} = 10 mA$
now current gain factor $ \beta = \frac{i_{C}}{i_{B}} $
$ \Rightarrow i_{B} = \frac{10mA}{250} = 40 \mu A $
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Concepts Used:
Semiconductors
Semiconductors are a crystalline solid materials, whose electrical conductivity lies between a conductor and an insulator. Semiconductors are mainly used in the manufacturing of electronic devices like capacitors, transistors, diodes, Integrated circuits, etc.
Properties of Semiconductor:
- Semiconductor acts like an insulator at Zero Kelvin. On increasing the temperature, it works as a conductor.
- Due to their exceptional electrical properties, semiconductors can be modified by doping to make semiconductor devices suitable for energy conversion, switches, and amplifiers.
- Lesser power losses.
Uses of Semiconductor:
- Semiconductors are widely used in manufacturing electronics devices like transistors, diodes, sensors, integrated circuits.
- Semiconductors are widely used in all electronic devices, like mobile phones, digital cameras, communication devices, trains, ATMs, etc.