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 → Electrostatics ↓


Electric charge and conservation


Electric charge is a fundamental property of matter that is responsible for electric forces. In simple terms, electric charge helps explain why and how particles attract or repel each other. In the field of physics, particularly electrostatics, understanding electric charge and its conservation is essential to explain a variety of phenomena.

Understanding electric charge

Electric charge is a fundamental property of the elementary particles of matter. There are two types of charge: positive and negative. Conventional wisdom dictates that like charges repel each other, while opposite charges attract each other. This principle forms the basis for understanding electrostatic forces and interactions.

Imagine two balloons rubbed with wool. When they are brought close to each other, they are repelled from each other. This happens because both balloons acquire the same kind of electrical charge. Conversely, a charged balloon can attract small pieces of paper, which is an example of opposite charges attracting.

Units and measurements

In the International System of Units (SI), charge is measured in coulombs (C). The charge of an electron is approximately -1.6 × 10 -19 coulombs, and the charge of a proton is +1.6 × 10 -19 coulombs.

Conservation of charge

The principle of conservation of charge states that the total electric charge in an isolated system remains constant. In simple terms, the total charge is conserved; it can be transferred from one body to another, but it cannot be created or destroyed.

Consider a closed system where two neutral atoms collide. If one atom gains an electron and becomes negatively charged, the other atom loses an electron, and becomes positively charged. The total charge remains the same before and after the interaction. This is an example of charge conservation.

Visual example: charge interaction

+ -

In the above illustration, a positive charge (+) and a negative charge (-) experience attractive forces as indicated by the dashed line. This attractive interaction is a fundamental consequence of opposite electrical charges.

Conductors and insulators

Substances through which electric charge can flow easily are called conductors. For example, metals like copper and silver. In contrast, materials that do not allow electric charge to flow easily are called insulators, such as rubber and wood.

Think of a metal wire connected to a battery. The wire acts as a conductor, allowing charge to flow through the circuit. Meanwhile, the rubber wrapper around the wire acts as an insulator to prevent accidental shocks.

Charge quantization

Electric charge is quantized, which means it can only exist in discrete packets called "quanta." The magnitude of the charge is always an integer multiple of the elementary charge (e), which is the charge of the proton or electron.

Charge (q) = n × e

where n is an integer, and e is the elementary charge. This principle implies that you cannot keep a fraction of the electron's charge as an independent charge unit.

Lesson example: charging by friction

When you rub a glass rod with silk, electrons are transferred from the glass to the silk. This makes the glass rod positively charged and the silk negatively charged. The total charge before and after the process remains zero, which shows charge conservation.

Elementary particles and charge conservation

Charge conservation applies not only to macroscopic interactions, but also to interactions at the atomic and subatomic levels. When particles interact in high-energy physics experiments, the net charge remains constant.

Visual example: interaction between two charged particles

+ +

In this example, two equal positive charges (+) repel each other as shown by the solid line pointing away. This is a clear illustration of the repulsive force between like charges - a fundamental aspect of electrostatic interactions.

Conclusion

Understanding electric charge and its conservation is important for understanding a variety of phenomena in physics. Electric charge affects the way particles and objects interact, and is governed by fundamental laws such as conservation of charge. These principles are not only essential for academic understanding, but also have practical applications in electronics, engineering, and various scientific fields.


Grade 11 → 6.1.1


U
username
0%
completed in Grade 11

← Prev (6.1)
Electrostatics
Next (6.1.2) →
Coulomb's law and its applications

Comments 



Electric charge and conservation

https://www.physicsflow.com/g11/6.1.1?pfal=en