Understanding Light, Atomic Models, and Quantum Mechanics
Nature of Light
Early Theories: Newton proposed that light consists of particles (corpuscular nature), while Huygens suggested a wave-like nature. Young demonstrated that light could be diffracted.
Wave Definition
A wave is the propagation of a vibrational disturbance that transmits energy, but not matter. Any wave is characterized by its amplitude, frequency, and wavelength.
Maxwell’s Electromagnetic Theory
Maxwell’s theory considers light as an electromagnetic wave, a non-material entity. The electromagnetic
Read MoreElectrical Installation Zones & Conductor Standards
Altitude-Based Electrical Installation Zones
Zone A: Below 500 Meters Altitude
Zone A is located within 500 meters of altitude above sea level. No overhead ice load is taken into account.
Zone B: 500 to 1000 Meters Altitude
Zone B is situated at an altitude of between 500 and 1000 meters. Bare conductors are considered subject to the overhead of a sleeve of ice worth 180 * d grams per meter, where d is the conductor diameter in mm. On the wire in the overhead beam, 60 * d grams per meter will be considered,
Read MorePhysics Concepts: Photoelectric Effect, Superconductivity, and More
Photoelectric Effect and Superconductivity
Photoelectric effect: The energy needed to remove an electron from a surface. φ is the minimum energy needed for an electron to escape. Light consists of photons, and one photon is absorbed by one electron. An electron can escape if hf > φ. The kinetic energy of an emitted electron is less than hf – φ. Electrons below the surface do work to reach the surface.
Superconductivity: A material has zero resistance. Resistance decreases with temperature until
Read MoreMechanics: Statics, Dynamics, and Motion Analysis
Statics and Dynamics
Statics is the area of mechanics that studies bodies at rest or in equilibrium as a result of forces acting on them. Dynamics is the area of mechanics that studies bodies in motion.
Kinematics and Kinetics
Kinematics is the study of the relationships between the displacements, velocities, and accelerations in translational or rotational motion. Kinetics studies bodies in motion and the forces acting to produce them.
Force
A force is a push or pull on a body. To produce a force, one
Read MoreElectrostatics Problems: Charges, Forces, and Fields
Iron atoms have been detected in the sun’s outer atmosphere, some with many of their electrons stripped away. What is the net electric charge (in coulombs) of an iron atom with 26 protons and 7 electrons? Be sure to include the algebraic sign (+ or -) in your answer.
Four identical metallic objects carry the following charges: +1.6, +6.2, -4.8, and -9.4 micro Coulombs. The objects are brought simultaneously into contact, so that each touches the others. Then they are separated. (a) What is the final
Read MoreMagnetic Fields and Forces: Key Concepts and Applications
Magnetic Force on a Moving Charge
The magnitude of the force is proportional to the value of the load and the magnitude of the velocity with which it moves. The direction of the force depends on the direction of that velocity.
Helical Path
If the charged particle has a velocity component parallel to the magnetic field and one perpendicular, it follows a helical path.
Conductor Inside a Magnetic Field
The magnetic field interacts with each of the charged particles whose motion produces the current. The
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