Work done by a magnetic field on a moving charge

Magnetic fields do no work on charged particles that travel through them – at least, not by the definition of work in physics. So a charged particle in a magnetic field doesn’t gain or lose kinetic or potential energy. In this post, we will see how to find out the work done by a magnetic […]

Magnetic field in solenoid – formula, direction

In this post, we will discuss the Magnetic field in a solenoid. We will also study the formula of the magnetic field in a solenoid and how to find out the direction of the magnetic field in a solenoid [polarity at the end of the solenoid] using the right-hand grip rule. Magnetic field in a […]

Path of a Charged Particle in a Uniform Magnetic Field

Path of a Charged Particle in a Uniform Magnetic Field – The direction of the initial motion of a charged particle in an external magnetic field determines how the charged particle will deflect. Figure 1 shows what can happen to a charged particle as it enters an external magnetic field: Path of a Charged Particle […]

Solenoid – magnetic field

A long closely wound helical coil is called a solenoid. Fig 1 shows a section of a stretched-out solenoid. Solenoid and its magnetic field The magnetic field due to the solenoid is the vector sum of the magnetic fields due to current through individual turns of the solenoid. The magnetic fields associated with every single […]

Biot-Savart Law statement, formula, derivation

In this post, we will cover the Biot-Savart Law statement, formula, and derivation. Biot and Savart conducted many experiments to determine the factors on which the magnetic field due to current in a conductor depends.The results of the experiments are summarized as Biot-Savart law. Biot-Savart law Let us consider a conductor XY carrying a current […]

Definition of ampere

Definition of ampere will be obtained here from the equation of the force between two parallel wires carrying currents. The force between two parallel wires carrying currents on a segment of length L is F = (μ0I1I2L) / (2πr) ∴ Force per unit length of the conductor is F/L =(μ0I1I2) / (2πr) If I1 = […]

Force between two long parallel current-carrying conductors

In this post, we will obtain the formula of the Force between two long parallel current-carrying conductors. AB and CD are two straight very long parallel conductors placed in the air at a distance r. They carry currents I1 and I2 respectively. (Fig 1). The magnetic field due to current I1 in AB at a […]

Force on a moving charge in a magnetic field – formula

When a charged particle (or charge) moves in a magnetic field, a magnetic force acts upon it. In this post, we will discuss this and obtain the formula of the Force on a moving charge or a charged particle in the magnetic field. This force is the magnetic component of the well-known Lorentz force on […]

Ampere’s Circuital Law – statement, formula

This post covers Ampere’s Circuital Law with its statement and formula. Ampere’s Circuital Law in electromagnetism is analogous to Gauss’ Law in electrostatics. Ampere’s Circuital Law – statement Ampere’s Circuital Law states that the line integral of the magnetic field B around any ‘closed’ path is equal to μ0 times the net charge I passing […]

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 […]

Applications of generators and motors

In this post, we will briefly discuss the different applications of generators and motors. Applications of generators and motors in cars Alternator in cars A car contains an alternator that charges its battery and powers the car’s electric system when its engine is running. Alternators have the great advantage over direct-current generators of not using […]

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 […]

Force Between Parallel Currents – how to derive the formula

Here, we will find out the formula of the force that acts between parallel currents. Force Between Parallel Currents – deriving the formula Consider two long wires kept parallel to each other such that the separation d between them is quite small as compared to their lengths. Suppose currents I1 and I2 flow through the […]

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 […]

Transformer – what is it and how it works?

What is a transformer? A transformer is used to change or transform alternating potential difference between (a) the power station and the cables, and (2) between the cables and our home. A typical power station generator produces an alternating potential difference in Kilo Volt(KV) range (like 25 KV). The electricity is delivered via a network […]

9 Worksheets on Electromagnetism [MCQ] | Multiple Choice Questions from the Electromagnetism chapter – physics

Here we present MCQ worksheets on Electromagnetism. Get these worksheets containing Multiple Choice Questions with their answers on topics like electromagnetism basics, electromagnet, power generation or electricity generation, etc. Also, you will find other types of exercises (like fill in the blanks and matching) with answers. Electromagnetism – MCQ Worksheet (with answer) – set 1 […]

Magnetic field lines of permanent magnets & current-carrying wires | How to calculate the magnetic field at an arbitrary distance from the wire?

Let’s learn the idea of magnetic field lines of permanent magnets & current-carrying wires, how these lines behave in the situation of permanent magnets and current-carrying wires, and also how to calculate the magnetic field at an arbitrary distance from the current-carrying wire. You can quickly revise the Magnetic field and magnetic field line properties […]

[pdf notes] Generator, motor & electrodynamics – grade 12 Notes download | class 12 physics notes on Generator, motor & electrodynamics

This Generator, motor & electrodynamics Notes [PDF] is primarily for the 12th grade physics syllabus of different international boards. This also covers the class 12 physics syllabus on Generator, motor & electrodynamics for boards like ICSE, CBSE, etc. This physics class note covers the theoretical as well as the numerical part of this important chapter. […]

Generator Effect and Motor Effect – underlying Physics principle

Generator Effect and Motor Effect – Fleming’s left-hand rule and right-hand rule are the 2 key guidelines to discuss generator effect and motor effect. We will discuss these effects with underlying principles as well as find out the differences between the motor effect and the generator effect. The Left-hand rule of Fleming tells us about […]

Electromagnetism: Fleming’s Left hand Rule, Right Hand Rule, Maxwell’s Right hand thumb/grip rule with statements and uses

Let’s find out a few interesting incidents of electromagnetism and in the process let’s discuss a few physics Laws or rules like Maxwell’s Right-hand thumb rule or Right-hand grip rule of Maxwell, Fleming’s Left-hand rule, and Fleming’s Right-hand rule and their uses and statements. We also figure out motor law and dynamo law (or generator […]

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