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


Magnetism and electromagnetism are fundamental concepts in physics, especially when discussing electricity and magnetism. In this comprehensive lesson, we will explore how these phenomena work, interact, and affect our daily lives through scientific principles and examples.

Understanding magnetism

Magnetism is the force exerted by magnetic fields. A magnetic field is the region around a magnetic material or a moving electric charge within which the force of magnetism acts.

Magnetic field

The magnetic field is represented by field lines that emerge from the north pole of the magnet and enter the south pole. These lines form continuous loops and never cross each other.

N S

This view shows a simplified diagram of the magnetic field lines around a bar magnet. The lines show how the field propagates from the north (N) to the south (S) pole.

Magnetic force

Magnetic forces are produced when magnets align or repel depending on the orientation of their magnetic poles. Like poles repel each other, while opposite poles attract.

For example, if you place two bar magnets with their north poles facing each other, they will repel each other. On the other hand, if the north pole and south pole face each other, they will attract.

Electromagnetism

Electromagnetism involves the study of electricity and magnetism. It explains how electric currents and magnetic fields interact.

Electric currents and magnetic fields

A wire carrying electric current produces a magnetic field around it. The right-hand rule is a common technique for determining the direction of this magnetic field.

Right hand rule: If you point the thumb of your right hand in the direction of the electric current, the fingers bend in the direction of the magnetic field.
B I

This diagram shows a wire carrying current (I) upwards, and the magnetic field (B) around it is directed in circular loops.

Formulas related to magnetism and electromagnetism

The strength of the magnetic field (B) produced by a long straight wire carrying current can be calculated using Ampere's law:

B = (μ₀ * I) / (2π * r)

Where:

  • B is the magnetic field strength (Tesla, T)
  • μ₀ is the permittivity of free space (4π x 10⁻⁷ T·m/A)
  • I is the current (ampere, A)
  • r is the distance from the wire (meters, m)

Electromagnetic induction

Electromagnetic induction is the process of producing electric current with a magnetic field. It occurs when a conductor, such as a coil of wire, is passed through a magnetic field. The change in the magnetic field induces a voltage, causing a current to flow when the circuit is closed.

This principle is the basis of transformers, generators and induction motors, which play a vital role in power generation and distribution.

Faraday's law of electromagnetic induction determines the amount of induced electric potential:

ε = -N * (ΔΦ/Δt)

Where:

  • ε is the electromotive force (EMF)
  • N is the number of turns in the coil
  • ΔΦ is the change in magnetic flux (Weber, Wb)
  • Δt is the change in time (seconds, s)

Applications of magnetism and electromagnetism

Magnetism and electromagnetism have many applications in technology and industry. Understanding these applications helps us understand how they shape modern life.

Electrical motors

Electric motors convert electrical energy into mechanical energy using electromagnetic principles. They contain coils of wire that carry current, producing a magnetic field that interacts with permanent magnets to produce motion.

Common uses for electric motors include home appliances, electric vehicles, and industrial machines.

Transformers

Transformers modify the voltage of electrical power in AC circuits. They use electromagnetic induction to transfer electrical energy between circuits, adjusting voltage levels for practical use.

For example, power plants generate high-voltage electricity for efficient transmission over long distances, then transformers reduce the voltage for safe use in homes and businesses.

Medical imaging

Magnetic resonance imaging (MRI) is a medical application of electromagnetism. It uses strong magnetic fields and radio waves to make detailed images of organs and tissues inside the body.

Magnetism in everyday life

Magnetism is not only a scientific concept, but also a phenomenon we encounter in everyday life. Here are some everyday examples:

  • Refrigerator magnets stick to metal surfaces.
  • Compass needles point towards north because of the Earth's magnetic field.
  • Headphones and speakers convert electrical signals into sound waves via electromagnetic fields.

Safety with magnetism and electromagnetism

Although magnetism and electromagnetism are incredibly useful, they must be handled responsibly:

  • Strong magnetic fields can affect electronic devices, such as credit cards and phones.
  • High-voltage electromagnetic equipment should only be operated by qualified personnel.

Conclusion

Magnetism and electromagnetism are integral parts of our physical world, and understanding them advances our understanding of nature and technology. These principles power innovations and applications that significantly impact the way we live our lives.


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Magnetism and Electromagnetism

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