The short note of

1. Resistor
2. Diode
3. Transformer



Resistor is a passive two terminal electrical component used for limiting or regulating the flow of electricity in a circuit. The SI unit of resistor is Ohm. There are two types of resistors which are Linear resistor and Non-linear resistor.



(a) It is made of copper wires which are coiled around a ceramic rod and outer part is coated with an insulating paint.

(b) Resistor can either change the value or can’t change it, because other resistors do not have specific value. For example, fixed resistors such as carbon composition wire wound thin film and thick film resistor.

(c) Resistor has one connection and two terminals

(d) It is one of the important components of the circuit, at in every circuit there are several resistors.


(a) Resistor are used for controlling temperature and voltmeter.

(b) Used to reduce the current flow and to lower the voltage in any particular portion of the circuit.

(c) Resistors are used in digital multimeter, amplifier and telecommunication.



Diode is an electronic device they allow the current to flow through it on one direction only. There are several types of diodes which are Light Emitting Diode (LED) Laser, Avalanche, Zener, Schottky, Photodiode and PN Junction diode.



(a) It is active electronic device made of either of the two semiconductors material silicon and germanium

(b) The arrow in the diode symbol represents the direction of conventional current flow in the forward-biased condition when the diode conducts.

(c) Transmit current in a single direction.


(a) Diode are used to protect circuit by limiting the voltage

(b) Diode used to transform AC into DC because it can used as rectifier or to form a rectifier.

(c) Used for emitting an infrared light spectrum.

(d) It works as a photodetector.



Transformer is a device used for stepping up or stepping down AC voltage. The types of transformers are classified based on the factors like working voltage the medium used in the core winding arrangement and installation location.


(a) It is made up of primary and secondary coil or winding and the core.

(b) In step-up transformer the output voltage is increased and in step-down transformer the output voltage is decreased.

(c) The step-up transformer will decrease the current and step-down transformer will increase the output current for keeping the input and output power of the system equal.


The transformer voltage control device that is used widely in the distribution and transmission of alternating current power, Also;

-Used to transfer electrical energy from circuit to another.

-Used to transfer electrical power without any change in frequency.

-Used to transfer power through electromagnetic induction.


Leave your comment:

You may also like;-

Follow Us:

Facebook Instagram