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


Electricity and magnetism are fundamental aspects of physics that play a vital role in understanding the world around us. In this detailed guide, we will discuss in depth the basic principles and concepts related to electricity and magnetism, providing a comprehensive overview that connects theoretical knowledge with practical examples.

Electricity

What is electricity?

Electricity is a type of energy that results from the existence of charged particles such as electrons or protons. It can manifest as static electricity or current. The flow of electrical charges is known as electric current.

Static electricity

Static electricity is the result of an imbalance between negative and positive charges in an object. These charges can accumulate on the surface of an object until they find a way to escape or be discharged.

For example, when you rub a balloon on your hair, electrons move from your hair to the balloon, leaving the balloon negatively charged and your hair positively charged. This static electricity can be demonstrated with a simple experiment:

1. Rub the balloon on your hair.
2. Slowly bring the balloon near the small pieces of paper.
3. Watch carefully how the pieces of paper are attracted to the balloon.

Electric current

Electric current is the flow of electric charge. It is measured in amperes (A). The flow of electrons through a conductor such as a copper wire is what creates electric current.

In this example diagram, imagine the circle as a conducting wire with flowing electrons.

Ohm's law

One of the fundamental principles of electricity is Ohm's Law. This law states that the current flowing through a conductor between two points is directly proportional to the voltage at the two points and inversely proportional to the resistance between them. Mathematically, it is expressed as:

I = V / R

Where I is the current in amperes, V is the voltage in volts, and R is the resistance in ohms.

For example, if you have a 12 volt battery connected to a 4 ohm resistor, the current flowing through the circuit can be calculated as:

I = 12V / 4Ω = 3A

Electric circuits

An electrical circuit is a closed loop that allows current to flow. It typically consists of a power source (such as a battery), a load (such as a light bulb), and conductive wires connecting these components. Circuits may be series or parallel, which affects the flow of electricity and the overall resistance.

Series and parallel circuits

In a series circuit, the components are connected end-to-end, so there is only one path for current to flow. The total resistance is the sum of the individual resistances:

R_total = R1 + R2 + ... + Rn

In a parallel circuit, components are connected to the same voltage source, creating multiple paths for current flow. The total resistance is given by:

1/R_total = 1/R1 + 1/R2 + ... + 1/Rn

The above figure shows a simplified representation of a parallel circuit, where resistors form multiple paths for the current.

Magnetism

What is magnetism?

Magnetism is the force exerted by magnets when they attract or repel each other. It is the property of materials that respond to an applied magnetic field. Magnetism is closely related to electricity; one generates the other.

Magnetic field

The magnetic field is a vector field around a magnet where the magnetic force is applied. The magnitude of the magnetic field is measured in Tesla (T). A common demonstration of a magnetic field is with iron filings around the magnet, showing the field lines.

This SVG shows the north (N) and south (S) poles of a bar magnet, with outer and inner arrows showing the direction of the magnetic field lines.

Electromagnetism

Electromagnetism is the interaction between electric currents and magnetic fields. When electric current passes through a wire, it creates a magnetic field around it. Conversely, a changing magnetic field can induce an electric current in a nearby conductor. This principle is the basis of many technologies, including transformers and electric generators.

A simple example of an electromagnet is to wrap a coil of wire around a metal core and then pass current through the coil. The metal core acts as a magnet, which can be turned on and off with the flow of current.

Maxwell's equations

Maxwell's equations describe the fundamentals of electricity and magnetism. They explain how electric and magnetic fields interact and how they can generate each other. These equations are essential to understanding classical electromagnetism. The equations are:

∇ · E = ρ/ε₀ --- Gauss's law for electricity
∇ · B = 0 --- Gauss's law for magnetism
∇ × E = -∂B/∂t --- Faraday's law of induction
∇ × B = μ₀(J + ε₀∂E/∂t) --- Ampere-Maxwell law

Applications of electricity and magnetism

Electrical power generation

Electricity is generated in power plants using the principles of electromagnetism. By rotating coils of wire in magnetic fields, electric current is generated, which can be transported long distances to power homes and industries.

Electronics

Electricity powers everyday electronic devices such as smartphones, computers, and televisions. These devices rely on the manipulation of electrical currents through semiconductors and circuit boards to perform various functions.

Communication systems

Electric and magnetic fields are fundamental to communication systems. Radio, television and wireless communications rely on electromagnetic waves to transmit information over distances.

Magnetic resonance imaging (MRI)

Magnetic fields are used in medical imaging techniques such as MRI. This technique creates detailed images of organs and tissues within the body using powerful magnets and radio waves.

Conclusion

Electricity and magnetism are intertwined and fundamental to modern life. From powering homes and gadgets to facilitating complex technological processes, understanding these principles is vital. The study of electricity and magnetism provides a glimpse into the invisible forces that drive the physical world and inspires further scientific exploration.


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