Grade 11
  1. Mechanics  1.1. dynamics  1.1.1. Motion in one dimension  1.1.2. Motion in two and three dimensions  1.1.3. Displacement and Distance  1.1.4. Speed and Velocity  1.1.5. Acceleration and deceleration  1.1.6. Graphical analysis of motion  1.1.7. Equations of motion (advanced derivations)  1.1.8. Free fall and terminal velocity  1.1.9. Projectile motion  1.1.10. Relative velocity in one and two dimensions  1.1.11. Motion of a car on an inclined plane  1.2. Dynamics  1.2.1. Newton's laws of motion and their applications  1.2.2. Inertia and Newton's first law  1.2.3. Force and types of force  1.2.4. Static and kinetic friction  1.2.5. Circular motion and centripetal acceleration  1.2.6. Non-uniform circular motion  1.2.7. Banking of roads and curves  1.2.8. Momentum and Impulse  1.2.9. Conservation of momentum in one and two dimensions  1.2.10. Applications of Newton's Third Law  1.3. Work, Energy and Power  1.3.1. Work done by a constant and variable force  1.3.2. Work–energy theorem  1.3.3. Kinetic and potential energy  1.3.4. Gravitational and elastic potential energy  1.3.5. Conservation of mechanical energy  1.3.6. Power and instantaneous power  1.3.7. Efficiency of machines  1.3.8. Work done by conservative and non-conservative forces  1.4. Rotational motion  1.4.1. Torque and angular acceleration  1.4.2. Rotational equilibrium  1.4.3. Moment of inertia and its applications  1.4.4. Angular momentum and its conservation  1.4.5. Kinetic energy of rolling motion and rotation  1.4.6. Parallel and Perpendicular Axis Theorem  1.4.7. Dynamics of rotational motion
  2. Gravitational force  2.1. Universal gravitation  2.1.1. Newton's law of universal gravitation  2.1.2. Gravitational field and potential  2.1.3. Change in acceleration due to gravity  2.1.4. Kepler's laws of planetary motion  2.1.5. Orbital mechanics and satellites  2.1.6. Escape velocity and orbital velocity  2.1.7. Weightlessness and free fall  2.1.8. Gravitational potential energy and energy in orbits  2.1.9. Black holes and gravitational lensing
  3. Properties of matter  3.1. Fluid mechanics  3.1.1. Density and pressure in liquids  3.1.2. Pascal's theory and applications  3.1.3. Archimedes' Principle and Buoyancy  3.1.4. Bernoulli's equation and applications  3.1.5. Continuity equation and the Venturi effect  3.1.6. Surface tension and capillarity  3.1.7. Viscosity and Poiseuille's Law  3.1.8. Reynolds number and turbulence  3.2. Elasticity and deformation  3.2.1. Hooke's law and the stress-strain relation  3.2.2. Elastic modulus and applications  3.2.3. Deformation and yield strength of solids
  4. Thermal physics  4.1. Heat and temperature  4.1.1. Thermometric properties and temperature scale  4.1.2. Thermal expansion of solids, liquids and gases  4.1.3. Heat transfer system  4.1.4. Specific heat capacity and calorimetry  4.1.5. Latent heat and phase change  4.2. Kinetic theory of gases  4.2.1. Molecular model of gases  4.2.2. Kinetic explanation of temperature  4.2.3. Ideal Gas Equation and Deviations  4.2.4. Mean free path and Maxwell–Boltzmann distribution  4.3. Laws of Thermodynamics  4.3.1. Zeroth Law and Thermal Equilibrium  4.3.2. First Law and Internal Energy  4.3.3. The Second Law and Entropy  4.3.4. Carnot cycle and heat engines  4.3.5. Refrigerators and heat pumps
  5. Waves and oscillations  5.1. Simple Harmonic Motion  5.1.1. Equations of SHM  5.1.2. Energy in SHM  5.1.3. Damped and forced oscillations  5.1.4. Resonance and applications  5.1.5. Pendulum and spring-mass system  5.2. Wave motion  5.2.1. Types of mechanical waves  5.2.2. Wave motion and energy transport  5.2.3. Superposition Principle and Standing Waves  5.2.4. Reflection, Refraction and Diffraction  5.2.5. Doppler effect in sound and light  5.2.6. Pulsations and interference
  6. Electricity and Magnetism  6.1. Electrostatics  6.1.1. Electric charge and conservation  6.1.2. Coulomb's law and its applications  6.1.3. Electric field and electric flux  6.1.4. Electric potential and potential energy  6.1.5. Capacitance and Energy Stored in a Capacitor  6.2. Current Electricity  6.2.1. Ohm's law and electrical resistance  6.2.2. Resistivity and temperature dependence  6.2.3. Kirchhoff's Laws and Circuit Analysis  6.2.4. Electrical power and efficiency  6.2.5. Combination of resistors  6.3. Magnetism and Electromagnetism  6.3.1. Magnetic fields and their sources  6.3.2. Magnetic force on moving charges  6.3.3. Electromagnetic induction  6.3.4. Faraday's and Lenz's laws  6.3.5. Inductance and Transformer  6.3.6. Alternating current and its applications
  7. Optics  7.1. Reflection and Refraction  7.1.1. laws of reflection and refraction  7.1.2. Mirrors and lenses  7.1.3. Total internal reflection and optical fiber  7.2. Wave optics  7.2.1. Interference and Diffraction  7.2.2. Young's double-slit experiment  7.2.3. Polarization of light
  8. Modern Physics  8.1.1. Photoelectric effect and Einstein's theory  8.1.2. Wave–particle duality  8.1.3. Heisenberg's uncertainty principle  8.1.4. Compton Effect  8.2. Atomic and Nuclear Physics  8.2.1. Atomic model and energy levels  8.2.2. Radioactive decay and half-life  8.2.3. Nuclear Fission and Fusion
  9. Electronics and Communication  9.1. Semiconductors  9.1.1. pn junction and diode  9.1.2. Transistors and Logic Gates  9.1.3. Integrated Circuits and Applications  9.2. Communication Systems  9.2.1. Basics of Analog and Digital Communication  9.2.2. Wireless and Optical Communication  9.2.3. Modulation and Demodulation

Grade 11 → Electricity and Magnetism ↓


Magnetism and Electromagnetism


Magnetism and electromagnetism are fascinating topics in physics that deal with the properties and interactions of magnetic fields and electric currents. Together, they form a vital part of our understanding of how electric and magnetic forces work, and they have countless applications in modern technology.

Magnetism

Magnetism is a force that results from the movement of electric charges. It is a fundamental property of certain materials that allows them to attract or repel other materials. The most common example of magnetism is a magnet, which is an object that produces a magnetic field.

A magnetic field is the region around a magnetic material or a moving electric charge, where the force of magnetism can be observed. You can think of it as an invisible field that surrounds a magnet and exerts a force on other magnetic objects within the field.

Magnetic field lines

In the figure above, the rectangle represents a magnet, and the lines are magnetic field lines, which show the direction of the magnetic force. The red lines represent the north direction, while the blue lines represent the south direction. This illustration helps us understand that the magnetic field lines emerge from the north pole of the magnet and enter the south pole.

Magnetic pole

Magnets have two poles: north (N) and south (S). These poles are the areas where the magnetic force is the strongest. When you bring two magnets close to each other:

  • Like poles (NN or SS) repel each other.
  • Opposite poles (NS) attract each other.

The behaviour of magnetic poles is an essential aspect of magnetism. Understanding this helps us in various applications such as a compass, where the needle aligns itself with the Earth's magnetic field.

Earth's magnetism

The Earth itself acts like a giant magnet. Its magnetic field extends all the way around the planet. That's why a compass works - it aligns with the Earth's magnetic field. The Earth's magnetic poles are not the same as its geographic poles, which is why a compass points to magnetic north rather than true north.

Electromagnetism

Electromagnetism is the interaction between electricity and magnetism. It involves how a magnetic field is produced by a moving electric charge and how a magnetic field can induce an electric current in a conductor.

Oersted's experiment

The connection between electricity and magnetism was discovered by Hans Christian Oersted in 1820. He observed that the needle of a magnetic compass deflected when an electric current flowed through a nearby wire. This discovery showed that electric currents produce magnetic fields.

Wire Magnetic Field

In the figure you can see that an electric current carrying wire produces a circular magnetic field around itself. This idea forms the basis of electromagnetism.

Electromagnetic induction

Electromagnetic induction refers to the process of producing electric current from a changing magnetic field. This principle was discovered by Michael Faraday in 1831. Faraday's experiments demonstrated that electric current can be induced in a wire when it is passed through a magnetic field or when the magnetic field around it changes.

Faraday's law of electromagnetic induction states:

The induced electromotive force (emf) in any closed circuit is equal to the negative of the time rate of change of the magnetic flux through the circuit.

Mathematically it is expressed as:

emf = -dΦ/dt

Where:

  • emf is the electromotive force in volts.
  • Φ is the magnetic flux in webers.
  • dt is the change in time in seconds.

Applications of magnetism and electromagnetism

Magnetism and electromagnetism have many applications in everyday life and technology:

Electrical motors

Electric motors convert electrical energy into mechanical energy. They work on the principles of electromagnetism, where a force is exerted on a current-carrying coil in a magnetic field.

Generator

Generators operate on electromagnetic induction to convert mechanical energy into electrical energy. When a coil of wire is rotated in a magnetic field, an electric current is induced in the wire.

Transformers

Transformers use electromagnetic induction to increase or decrease the voltage of alternating current (AC) electricity. They consist of two coils (primary and secondary) wrapped around a magnetic core. When AC flows in the primary coil, it induces a voltage in the secondary coil.

Conclusion

Understanding magnetism and electromagnetism is important for understanding how many modern devices and technologies work. These concepts highlight the complex relationships between electric and magnetic fields, which we use for a variety of applications that improve our quality of life.


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Magnetism and Electromagnetism

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