Grade 10
  1. Mechanics  1.1. Dynamics  1.1.1. Motion in one dimension  1.1.2. Motion in two dimensions  1.1.3. Displacement and Distance  1.1.4. Speed and Velocity  1.1.5. Acceleration  1.1.6. Graphical representation of motion  1.1.7. Equations of motion  1.1.8. Free fall and acceleration due to gravity  1.1.9. Projectile motion  1.1.10. Relative speed  1.2. Dynamics  1.2.1. Newton's Laws of Motion  1.2.2. Inertia and mass  1.2.3. Force and its types  1.2.4. action and reaction force  1.2.5. Friction and its effects  1.2.6. Coefficient of friction  1.2.7. Circular motion  1.2.8. Centripetal force and centripetal acceleration  1.2.9. Momentum and Impulse  1.2.10. Conservation of momentum  1.2.11. Newton's third law and applications  1.3. Work, Energy and Power  1.3.1. Work done by the force  1.3.2. Work–energy theorem  1.3.3. Kinetic energy  1.3.4. Potential energy  1.3.5. Mechanical energy  1.3.6. Energy Conservation  1.3.7. Power and efficiency  1.3.8. Renewable and non-renewable energy sources  1.4. Gravitational force  1.4.1. Newton's law of universal gravitation  1.4.2. Gravitational field and field strength  1.4.3. Acceleration due to gravity on different planets  1.4.4. Kepler's laws of planetary motion  1.4.5. Orbits and satellites  1.4.6. Weight and apparent weight  1.4.7. Gravitational potential energy
  2. Properties of matter  2.1. States of matter  2.1.1. Solid, liquid and gas  2.1.2. Molecular structure of matter  2.1.3. Intermolecular forces  2.1.4. Plasma and Bose–Einstein condensate  2.2. Pressure  2.2.1. Definition of Pressure  2.2.2. Pressure in liquids  2.2.3. Atmospheric pressure  2.2.4. Pascal's principle  2.2.5. Archimedes' Principle and Buoyancy  2.2.6. Surface tension and capillarity  2.3. Elasticity  2.3.1. Hooke's law  2.3.2. Stress and strain  2.3.3. Elastic Limit and Modulus of Elasticity  2.3.4. Applications of Elasticity
  3. Thermal physics  3.1. heat and temperature  3.1.1. Difference Between Heat and Temperature  3.1.2. Temperature scale  3.1.3. Thermal expansion  3.1.4. Thermal equilibrium  3.2. Heat transfer  3.2.1. Conductivity  3.2.2. Convection  3.2.3. Radiation  3.2.4. Insulation and its applications  3.3. Thermal properties of matter  3.3.1. Specific heat capacity  3.3.2. Latent heat and phase change  3.3.3. Boiling and Melting Point  3.3.4. Heat engines and refrigeration  3.4. Laws of Thermodynamics  3.4.1. Zeroth law of thermodynamics  3.4.2. First law of thermodynamics  3.4.3. Second law of thermodynamics  3.4.4. Carnot cycle
  4. Waves and optics  4.1. Nature and properties of waves  4.1.1. Types of waves in nature and properties of waves  4.1.2. Transverse and longitudinal waves  4.1.3. Wave parameters  4.1.4. Reflection and refraction of waves  4.1.5. Superposition and Interference  4.1.6. Standing Waves and Resonance  4.1.7. Doppler effect  4.2. Sound waves  4.2.1. Characteristics of sound waves  4.2.2. Speed of sound in different mediums  4.2.3. Applications of sound waves  4.2.4. Ultrasound and its uses  4.3. Light Waves and Optics  4.3.1. Nature of light  4.3.2. Reflection of light  4.3.3. Laws of reflection  4.3.4. Mirrors and Image Formation  4.3.5. Refraction of light  4.3.6. Snell's Law  4.3.7. Lenses and Image Formation  4.3.8. Total internal reflection and critical angle  4.3.9. Optical fibre  4.4. Optical Instruments  4.4.1. Microscope  4.4.2. Telescope  4.4.3. Human eye and vision defects  4.4.4. Camera and its working principle
  5. Electricity and Magnetism  5.1. Electrostatics  5.1.1. Electric charge and its properties  5.1.2. Conductors and Insulators  5.1.3. Coulomb's law  5.1.4. Electric field and field lines  5.1.5. Electric potential and potential difference  5.1.6. Capacitors and Capacitance  5.2. Current Electricity  5.2.1. Electric current and its measurement  5.2.2. Ohm's law  5.2.3. Resistance and resistivity  5.2.4. Series and Parallel Circuits  5.2.5. Electric power and energy  5.2.6. Kirchhoff's Laws  5.3. Magnetism and Electromagnetism  5.3.1. Magnetic field and field lines  5.3.2. Magnetic effects of electric current  5.3.3. Electromagnetic induction  5.3.4. Faraday's laws of electromagnetic induction  5.3.5. Transformers and Applications  5.3.6. AC and DC current
  6. Modern Physics  6.1. Nuclear physics  6.1.1. Structure of the atom  6.1.2. Bohr's atomic model  6.1.3. Electron Energy Levels  6.1.4. X-rays and applications  6.2. Radioactivity  6.2.1. Types of radiation  6.2.2. Half-life and radioactive decay  6.2.3. Nuclear reactions and applications  6.2.4. Fission and Fusion  6.3. Quantum physics  6.3.1. Wave–particle duality  6.3.2. Photoelectric effect  6.3.3. Energy quantization  6.3.4. Heisenberg's uncertainty principle
  7. Electronics and Communication  7.1. Semiconductors  7.1.1. Conductors, Insulators and Semiconductors  7.1.2. Diodes and their applications  7.1.3. Transistors and Logic Gates  7.1.4. LEDs and photodiodes  7.2. Communication Systems  7.2.1. Basics of communication  7.2.2. Analog and digital signals  7.2.3. Wireless and optical fibre communication  7.2.4. Radio Waves and Modulation

Grade 10 → Electricity and Magnetism → Magnetism and Electromagnetism ↓


Magnetic effects of electric current


In Grade 10 Physics, we explore the fascinating world of magnetism and electromagnetism. This subject delves deep into the interaction between electricity and magnetism, particularly focusing on the phenomenon known as the "magnetic effect of current". It is the foundation of modern technology, as it explains how electric currents can generate magnetic fields and how these principles are applied in various devices.

Understanding magnetism

Magnetism is a force in nature that causes substances to attract or repel each other. Permanent magnets are an example of magnetism, where certain substances generate a permanent magnetic field around them. The Earth itself is a giant magnet, and its magnetic field protects us from harmful radiations coming from space.

What is a magnetic field?

A magnetic field is an invisible field that exerts a force on magnetic materials such as iron. It is represented by magnetic field lines, which show the direction and strength of the magnetic force. The density of these lines indicates how strong the magnetic field is: closer lines mean the field is stronger.

Formula: B = F / (q(v)) // where B is the magnetic field, F is the force, q is the charge, and v is the velocity of the charge.

Visual example 1: Magnetic field lines around a bar magnet

N S

The figure above shows some field lines around a bar magnet. The lines start from the north pole and end at the south pole, showing the direction of the magnetic field.

Electric current and magnetism

In 1820, a Danish scientist named Hans Christian Oersted discovered a remarkable connection between electricity and magnetism. During a lecture, he observed that when electric current flowed through a wire, a compass needle located nearby deflected. This experiment demonstrated that electric currents create magnetic fields.

Magnetic field around a current carrying conductor

When electric current passes through a conductor, such as a wire, it creates a magnetic field around it. The direction of this magnetic field depends on the direction of the current. It can be determined using the right-hand rule. If you hold the conductor in your right hand and your thumb points in the direction of the flow of current, your fingers will bend in the direction of the magnetic field lines.

Visual example 2: Magnetic field around a straight current-carrying wire

I

In this diagram, the wire is shown vertically, with current flowing upwards. The circular magnetic field line is shown as a loop around the wire.

Factors affecting the magnetic field strength

  • Amount of current: Increasing the current increases the strength of the magnetic field.
  • Distance from the conductor: As you move away from the conductor, the strength of the magnetic field decreases.

Electromagnetic induction

The concept of electromagnetic induction is important to understanding how electric currents and magnetic fields interact. Michael Faraday discovered that a changing magnetic field within a closed loop of wire induces an electric current in the wire. This principle is fundamental to the operation of generators and transformers.

Faraday's law of electromagnetic induction

According to Faraday's law, the induced electromotive force (EMF) in any closed circuit is equal to the negative of the rate of change of magnetic flux passing through the circuit.

Formula: EMF = -dΦ/dt // Where Φ is the magnetic flux.

This means that the faster the magnetic field changes, the greater will be the induced EMF in the circuit.

Lenz's law

Lenz's law states that the direction of the induced current is such that it opposes the change in the magnetic flux that produces it. This is an important principle that ensures conservation of energy in electromagnetic systems.

Applications of magnetic effect of current

Understanding the magnetic effects of electric current has led to many applications that we use in our daily lives.

Electrical motors

Electric motors convert electrical energy into mechanical energy using the principles of electromagnetism. They are made up of coils of wire that rotate in a magnetic field due to the force exerted by electromagnetic induction.

Transformers

Transformers are used to increase or decrease voltage levels in power lines. They work on the basis of electromagnetic induction, in which primary and secondary coils transfer electrical energy through a changing magnetic field.

Visual example 3: Simplified diagram of a transformer

Primary Coil Secondary coil

A simplified transformer consists of a primary coil and a secondary coil connected to an iron core. When alternating current flows through the primary coil, it creates a changing magnetic field that induces current in the secondary coil.

Magnetic levitation

Maglev trains use the principles of electromagnetic fields to achieve frictionless, high-speed travel. Powerful magnets lift the train above the tracks, eliminating contact and thus resistance.

Conclusion

The magnetic effects of electric current are the backbone of many technologies we depend on every day. Understanding how electricity and magnetism interact allows us to harness these forces for many applications, from our homes to transportation systems. The concepts and rules discussed in this exploration provide the basis for advances in electrical and electronic systems.


Grade 10 → 5.3.2


U
username
0%
completed in Grade 10

← Prev (5.3.1)
Magnetic field and field lines
Next (5.3.3) →
Electromagnetic induction

Comments 



Magnetic effects of electric current

https://www.physicsflow.com/g10/5.3.2?pfal=en