Question -1:  Explain electronic, devices and circuit?
Ans. Electronics: Electronics is the science of how to control electrical energy, in which electrons play a fundamental role. It deals with electronic circuits and components.

  1. Devices: A thing made or adapted for a particular purpose especially a piece of mechanical or electronic equipment.
  2. Circuits: Electric current flows in a closed path called an electrical circuit.

Question -2: What is a transistor? Why transistor is called a transistor?
Ans: A transistor is a semiconductor device used to amplify and switch electronic signals and electronic power.
The name transistor is the combination of the word transfer and resistance i.e it is a resistor device which can amplify electric signals as they are transferred through it from input to output terminals.
Question -3: How a transistor amplifies?
Ans: When a small voltage difference is given to the input circuit the current will be very high because the resistance in the B-E junction is low. As the base is very thin and doped in a low level it cannot handle this electron flow. Therefore the most electrons slipped to the collector.  But as mentioned above the resistance in the B-C junction is very high. Therefore, the voltage difference in the output circuit will be greater than the original voltage difference. That is how transistors develop signals.
Question -4: What is biasing?
Ans: The bias is usually specified as the direction in which DC from a battery or power supply flows between emitter and base.
Question -5: What is a diode?
Ans: A semiconductor device with two terminals typically allowing the flow of current in one direction only.
Question -6: Why all electronic components work on DC?
Ans: Electronic devices usually require a steady DC supply. Direct current always flow in the same direction and is always of either positive or negative polarity. The electronics are made of transistors, diodes, switches which uses voltage as control signals. If the polarity is changing many times per second, the electronic circuit fails its purpose.
Question -7: What is regulated and unregulated power supply?
Ans: Regulated power supply provides constant voltage at the output and unregulated power supply provides variable voltage at the output.
Question -8: What is a rectifier?
Ans: A rectifier is an electrical device which converts an AC into pulsating DC by allowing a current to flow through one direction only.
Question –9: Why diode is required in circuits?
Ans: A diode works as a switch and is so fast that it turns on and off many times in a second which is not possible with the ordinary switch.