Magnetic Field lines due to a Current in a Solenoid

A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder is called a solenoid. The pattern of the magnetic field lines due to a Current in a Solenoid around that solenoid is shown in Fig. 1. If we compare the pattern of the field with the magnetic […]

Biot-Savart Law Numericals

Physics Numerical Problems Based on Biot Savart Law – The Biot-Savart law is a fundamental relationship in magnetostatics. It describes the magnetic field generated by a steady current. In this post, we will look at a set of numerical problems based on the Biot-Savart law and their step-by-step solutions. Formulas Used The Biot-Savart law allows […]

Permeability & Relative Permeability

In this post, we will discuss Permeability & Relative Permeability with their definition, relationship, equations, formula, the permeability of air, examples, etc. Permeability The ability of a material to conduct magnetic lines of force through it is called the permeability of that material. It is generally represented by μ (mu, a Greek letter). The greater […]

Aurora Borealis Aurorae | Aurora Australis

An effect caused by the Earth’s magnetic field is the spectacular Northern and Southern Lights, which are also called the Aurora Borealis (Figure 1) and the Aurora Australis respectively (Figure 2). When charged particles from the solar wind reach the Earth’s magnetosphere, they spiral along the magnetic field lines towards the North and South poles. […]

The importance of the Earth’s magnetic field to life on Earth

The Earth’s magnetic field is very important for humans and other animals on Earth because it protects us from being bombarded (struck) by high-energy charged particles, which are emitted by the Sun. The stream of charged particles (mainly positively charged protons and negatively charged electrons) coming from the Sun is called the solar wind. When […]

Magnetic fields due to different currents

An electric current can cause a magnetic field. The field patterns due to different currents can be seen in the diagrams below. The field pattern of a straight wire carrying current The direction of the field lines can be remembered with the right-hand grip rule. If the thumb of the right hand is arranged to […]

Comparison between electric field and magnetic field

A table of the comparisons between the electric field and the magnetic field is shown below. Electric Field Magnetic Field An electric field is caused by charges. But, a magnetic field is caused by magnets (or electric currents). The electric field affects charges. But, the magnetic field affects magnets (or electric currents). There are 2 […]

Electromagnets & its uses

We can make a magnet that we can switch on and off, using a coil of wire and a battery. It is called an electromagnet. Remember that, a bar magnet is not an electromagnet, rather it’s a permanent magnet. You cannot switch it off without demagnetizing it completely. In this post, we will discuss different […]

Electromagnetic Induction – Concepts with Revision Notes

In this post, we explore electromagnetic induction – the creation of an electric current from a changing magnetic field. Whether the primary source of energy is burning coal, falling water, nuclear fission, or the Sun, virtually all of the electricity generated in the world’s power stations is the result of electromagnetic induction. In fact, electromagnetic […]

The Transformer equation & Transformer efficiency

In this post we will discuss in detail about the transformer equation and transformer efficiency. We will also solve a few numerical problems using the transformer and efficiency equations. The Transformer equation The secondary potential difference of a transformer depends on the primary potential difference and the number of turns on each coil. You can […]


In this post, we will discuss the fundamentals of magnetism. Also, a number of related terminologies like magnetism, magnetic fields, ferromagnetism, paramagnetism, diamagnetism, permanent magnet, poles of magnets, magnetic attraction & repulsion, drawing field lines, a bar magnet, retentivity, compass, earth as a magnet, etc. , will be addressed. Define Magnetism Magnetism is an interaction […]

Magnetic Field & Magnetic Field Lines

This post defines the magnetic field and magnetic field lines. This also enlists the properties of magnetic field lines. What is Magnetic field? | Define magnetic field The space or area around a magnet in which its magnetic force can be felt is called a magnetic field. The magnetic field is a vector quantity i.e. it […]

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