Q1: What is a Transistor?
Ans: A transistor is a semiconductor device used to amplify or switch electronic signals.
Q2: State the uses of Transistors.
Ans: Uses of transistors are:
- ➔ Used as an amplifier
- ➔ Used as a switch
- ➔ Used in electronic circuits
- ➔ Used in communication systems
Q3: What is a Bipolar Junction Transistor?
Ans: A Bipolar Junction Transistor (BJT) is a transistor that uses both electrons and holes as charge carriers.
Q4: State the types of Bipolar Junction Transistors.
Ans: Types of BJT are:
- ➔ PNP Transistor
- ➔ NPN Transistor
Q5: What is a PNP Transistor?
Ans: A PNP transistor is a type of transistor in which a layer of N-type material is sandwiched between two P-type materials.
Q6: What is a NPN Transistor?
Ans: An NPN transistor is a type of transistor in which a layer of P-type material is sandwiched between two N-type materials.
Q7: Define Emitter.
Ans: The emitter is the terminal of a transistor that emits charge carriers (electrons or holes).
Q8: Define Base.
Ans: The base is the middle terminal of a transistor that controls the flow of charge carriers.
Q9: Define Collector.
Ans: The collector is the terminal of a transistor that collects charge carriers.
Q10: Briefly explain the working of a Transistor.
Ans: In a transistor, a small current at the base controls a larger current flowing from emitter to collector.
Thus, it can amplify signals.
Q11: What is the working principle of a Transistor?
Ans: The working principle of a transistor is based on the control of current flow by charge carriers through a semiconductor material.
Q12: Define Transistor Currents.
Ans: Transistor currents are the currents flowing through its terminals: emitter current (IE), base current (IB), and collector current (IC).
Q13: Define Transistor Gains. Write the formula.
Ans: Transistor gain is the ratio of output to input signal.
General formula:
Gain = Output / Input
Q14: Define Current Gain. Write the formula.
Ans: Current gain is the ratio of collector current to base current.
β = IC / IB
Q15: Define Voltage Gain. Write the formula.
Ans: Voltage gain is the ratio of output voltage to input voltage.
Av = Vout / Vin
Q16: Define Power Gain. Write the formula.
Ans: Power gain is the ratio of output power to input power.
Ap = Pout / Pin
Q17: What is a BJT Transistor?
Ans: A BJT transistor is another name for Bipolar Junction Transistor which uses both types of charge carriers.
Q18: State the terminals of BJT transistors.
Ans: Terminals of BJT are:
- ➔ Emitter
- ➔ Base
- ➔ Collector
Q19: State the uses of BJT as an Amplifier.
Ans: Uses of BJT as amplifier are:
- ➔ Audio amplification
- ➔ Signal amplification
- ➔ Radio and TV circuits
- ➔ Communication systems
Q20: Define Common Emitter Amplifier.
Ans: A common emitter amplifier is a transistor amplifier in which the emitter terminal is common to both input and output.
Q21: Define Common Base Amplifier.
Ans: A common base amplifier is a transistor amplifier in which the base terminal is common to both input and output.
Q22: Define Common Collector Amplifier.
Ans: A common collector amplifier is a transistor amplifier in which the collector terminal is common to both input and output.
Q23: Define Zener Diode.
Ans: A Zener diode is a special type of diode that allows current to flow in reverse direction when a certain voltage is reached.
Q24: What is Zener Biasing?
Ans: Zener biasing is the process of operating a Zener diode in reverse bias to maintain a constant voltage.
Q25: What is the rating of Zener Diode?
Ans: The rating of a Zener diode is defined by its Zener voltage and power dissipation capacity.
Q26: Explain Zener Diode as a Shunt Regulator.
Ans: In a shunt regulator, the Zener diode is connected parallel to the load.
It maintains constant voltage by allowing excess current to pass through it.
Q27: What is a Photo Diode?
Ans: A photodiode is a semiconductor device that converts light into electrical current.
Q28: State the uses of Photo Diode.
Ans: Uses of photodiode are:
- ➔ Light detection
- ➔ Solar energy systems
- ➔ Optical communication
- ➔ Light sensors
Q29: What is a Solar Cell or a Photo Voltaic Cell?
Ans: A solar cell is a device that converts sunlight directly into electrical energy.
Q30: State the working principle of a Solar Cell.
Ans: A solar cell works on the photovoltaic effect, where light energy is converted into electrical energy.
Q31: Briefly explain the construction and working of a Solar Cell.
Ans: A solar cell is made of a PN junction semiconductor.
When sunlight falls on it, electrons are excited and create current.
This current is collected and used as electrical energy.
Q32: Define LED.
Ans: LED (Light Emitting Diode) is a semiconductor device that emits light when current flows through it.
Q33: What is Biasing of LEDs?
Ans: Biasing of LEDs means applying proper forward voltage so that the LED emits light safely.
Q34: State the uses of LEDs.
Ans: Uses of LEDs are:
- ➔ Indicator lights
- ➔ Display panels
- ➔ Lighting systems
- ➔ Electronic devices
Q35: Define Dark Current.
Ans: Dark current is the small current that flows in a photodiode even when no light is present.
