High School Physics

Basic Electronics

P-Type Semiconductors – revision notes

P-type semiconductors are obtained by adding trivalent impurities (Boron, Gallium, Indium, Aluminum) to a pure semiconductor. The three valence electrons of the impurity atom form covalent bonds with neighboring semiconductor atoms and the fourth covalent bond has a vacancy. This gives rise to a hole in the semiconductor. Thus the addition of trivalent impurity atom […]

N-Type Semiconductors – revision notes

N-type semiconductors are obtained by adding pentavalent impurities (Bismuth, Antimony, Arsenic, and Phosphorous) to a pure semiconductor. The four valence electrons of the impurity atom form covalent bonds with four neighboring semiconductor atoms and the filth electron is free to move in the crystal. Thus the addition of pentavalent impurity atom provides free electrons to […]

Properties of P-type and N-type material & their differences

let us go through the properties of P-type and N-type semiconductors. Then we will compare P-type and N-type semiconductors, as well. P-type and N-type material In Figure 1, the left side material is a P-type semiconductor having negative acceptor ions and positively charged holes. The right side material is an N-type semiconductor having positive donor […]

Types of semiconductors – intrinsic (pure) and extrinsic (impure)

Semiconductors may be classified into 2 types: (1) Intrinsic (pure) semiconductors, and (2) Extrinsic (impure) semiconductors. In this post, we will learn more about intrinsic (pure) semiconductors, the Movement of Holes in Intrinsic or pure Semiconductors, Extrinsic (impure) semiconductors, and the purpose of adding impurity. Intrinsic (pure) semiconductors Semiconductor in its extremely pure form is […]

Commonly used semiconductors: Germanium & Silicon

There are many semiconductors available, but very few of them have practical applications in electronics. The two commonly used materials are Germanium (Ge) and Silicon(Si). In Ge and Si, the energy required to break the covalent bond (energy required to release an electron) is very small. For Ge, it is 0.7 eV and for Si, […]

Energy Bands in Solids – types of bands, & forbidden energy gap

In an isolated atom, the energy levels of electrons in various orbits can be represented by horizontal lines. Such a diagram is called Energy Level Diagram. Atoms of gases can be considered isolated because of their greater spacing under normal pressure and temperature. Hence the energy levels of such atoms are not affected by other […]

Explain how a Zener diode can be used as a voltage regulator

The Zener diode makes its use as a voltage regulator due to the following property:When a Zener diode is operated in the breakdown region, the voltage across it remains practically constant for a large change in the current. A simple circuit of a voltage regulator using a Zener diode is shown in Figure 1. The […]

Doping of semiconductors – revision notes

Doping is the process of adding impurity atoms to an intrinsic semiconductor material or semiconductor. Here, in this post, we will discuss the doping process in detail. semiconductors Germanium and silicon are examples of semiconductors. Silicon and germanium have a unique property in their electron structure. Each of these elements has four electrons in its […]

Light-dependent resistors (LDR) – fundamentals

A light-dependent resistor (LDR) is a semiconductor component with a resistance that depends on the intensity of the light that is incident on it. The greater the intensity, the lower the resistance of the LDR. How LDR works Light provides the energy to release charge carriers and decrease the resistivity of the material. Higher intensity […]

Measuring the resistance of a component – different ways

In this post, we are going to discuss different ways of measuring the resistance of a component. Resistance is defined as R = V/I. This obviously gives ways of measuring resistance, as in the circuits shown below. Each of the first 2 methods listed below uses both an ammeter and a voltmeter. And, the third […]

The semiconductor Diode – Revision notes

A diode is one of the simplest semiconductor devices, which has the characteristic of passing current in one direction only. However, unlike a resistor, a diode does not behave linearly with respect to the applied voltage as the diode has an exponential I-V relationship and therefore we can not describe its operation by simply using […]

Inductance & Inductor

In this post, we will discuss Inductance and inductor (choke) and the physics behind these.What is inductance? And what is an inductor? Inductance is the characteristic of an electrical conductor that opposes a change in current flow. An inductor is a device that stores energy within itself in the form of a magnetic field and […]

How to find resistance using Resistor Colour Codes

Small resistors use coloured or painted bands which represent their resistive value and tolerance. These coloured painted bands produce a system of identification generally known as a Resistors Colour Code. The physical size of the resistor indicates its wattage rating. Resistor Colour Code Table There are two types of resistor colour coding systems, the four-band […]

Semiconductors, doping, N-type and P-type, motion of electron & hole

In a semiconductor, electrons flow, but not as well as they do in a conductor. Some semiconductors carry electrons almost as well as good electrical conductors like copper or aluminum; others are almost as bad as insulating materials. Semiconductors are not exactly the same as resistors. In a semiconductor, the material is treated so that […]

Capacitors & Capacitance

Capacitors are components of electrical circuits that temporarily store electric charge. Capacitors are simple passive devices. The capacitor is a component that has the ability or “capacity” to store energy in the form of an electrical charge producing a potential difference across its plates. Capacitors consist of two or more parallel conductive metal or foil […]

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