Electromagnetic Waves, Sound & Wave Properties

Electromagnetic Waves, Sound & Wave Properties

Electromagnetic waves used in communication with wavelengths between about 1 cm and 20 cm are called (microwaves).

Electric signals that have only two possible values (on and off) are (digital signals).

A(n) (photon) is an electromagnetic wave that behaves like a particle.

Electromagnetic radiation with wavelengths between 400 and 750 billionths of a meter that can be detected by the human eye is (visible light).

A system of satellites, ground monitoring

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Semiconductor Electronics, P–N Junctions, Atomic Models & AC Physics

Semiconductor Electronics

Semiconductor

Semiconductor — These materials whose electrical conductivity lies between a conductor and an insulator are called semiconductors. At absolute zero they behave as insulators and at room temperature they behave as conductors.

Examples: Ge, Si, GaAs, CdS, CdSe, InP, etc.

Classification by Energy Band Theory

In solids there are three energy bands:

  • The lower band is completely filled by electrons and is called the valence band (VB).
  • The upper band is called the conduction
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Electric Charge, Fields, Potential and Current

Electric Charge and Electric Field

Electric charge — it is a property of a body; charged bodies exhibit attraction and repulsion.

Electric field

Electric field — the sphere around a source charge in which a test charge would experience a force is called the electric field.

Electric field lines

Electric field lines — an electric field is represented by imaginary lines of force which are called electric field lines.

Properties of field lines

  • They are imaginary lines of force.
  • They are not closed (they
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Electric Field, Potential, Capacitance & Current Notes

Chapter 1: Electric Field and Dipole

Electric Field

Electric field: The sphere around a source charge in which a test charge would experience a force is called the electric field.

Electric Field Lines

Electric field lines: An electric field is represented by imaginary lines of force which are called electric field lines.

Properties

  1. They are imaginary lines of force.
  2. In the case of a positive source charge they are radially directed outward.
  3. They are not closed lines.

Mathematical Definition of Electric Field

Mathematically

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Physics Laboratory Experiments: Ohm’s Law, Diodes, and Magnetism

Experiments in Electricity and Magnetism

Experiment 1: Verifying Ohm’s Law and Determining Resistance

To observe the variation of potential difference (V) across a given resistance with varying current (I), draw the I-V curve, and find the value of the given resistance from the graph.

Apparatus and Materials

  • Battery
  • Ammeter
  • Voltmeter
  • Resistance (unknown)
  • Rheostat
  • Key
  • Connecting wires
  • Sandpaper

Theory

Ohm’s law states that, provided the temperature remains constant, the current (I) flowing through a conductor

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Sports Biomechanics: Levers, Rotation, Newton’s Laws

Third-Class Lever Example: Knee Extension

Q1: An example of a third-class lever is knee extension (like kicking a ball), where the force is between the fulcrum and load. The knee joint is the fulcrum (the pivot point where the lower leg rotates), the quadriceps tendon, inserting on the tibial tuberosity, provides the effort in the middle, and the leg and foot (plus any ball) form the load at the far end.

Landing Technique: Shock Absorption in Gymnastics

Q2: Gymnasts bend their knees and flex their

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