5.1 Electric Charge

Electric charge is a fundamental property of matter that creates electromagnetic forces. Positive and negative charges interact, with like charges repelling and unlike charges attracting. This interaction forms the basis for understanding electric fields and forces.

Charge behavior is governed by ###Coulomb's_law_0###, which describes the force between charged particles. Charge is quantized, conserved, and can be transferred through various methods. Understanding these principles is crucial for grasping electromagnetism and its applications.

Electric Charge

Types of electric charge

Top images from around the web for Types of electric charge

• 

  5.6 Electric Field Lines – University Physics Volume 2 View original

  Is this image relevant?

• 

  Electrical Charge – Basic Electricity View original

  Is this image relevant?

• 

  Electric field lines of two charges – TikZ.net View original

  Is this image relevant?

• 

  5.6 Electric Field Lines – University Physics Volume 2 View original

  Is this image relevant?

• 

  Electrical Charge – Basic Electricity View original

  Is this image relevant?

1 of 3

Top images from around the web for Types of electric charge

• 

  5.6 Electric Field Lines – University Physics Volume 2 View original

  Is this image relevant?

• 

  Electrical Charge – Basic Electricity View original

  Is this image relevant?

• 

  Electric field lines of two charges – TikZ.net View original

  Is this image relevant?

• 

  5.6 Electric Field Lines – University Physics Volume 2 View original

  Is this image relevant?

• 

  Electrical Charge – Basic Electricity View original

  Is this image relevant?

1 of 3

• Electric charge is a fundamental property of matter causes it to experience a force when placed in an electromagnetic field measured in coulombs (C)
• Two types of electric charge exist: positive and negative
  • Like charges repel each other, while unlike charges attract each other (two positive charges push away from each other, while a positive and negative charge pull towards each other)
• Protons have a positive charge, electrons have a negative charge, and neutrons have no charge
  • An object with an equal number of protons and electrons is electrically neutral (an atom with 6 protons and 6 electrons has no net charge)
• Objects can become charged through various methods
  • Friction (rubbing a balloon on hair transfers electrons, making the balloon negatively charged)
  • Conduction (touching a charged object to a neutral object transfers charge)
  • Induction (bringing a charged object near a neutral object redistributes charge in the neutral object)
  • Polarization (separation of charges within a neutral object due to an external electric field)

Behavior of electric forces

• Electric forces are the attractive or repulsive forces between charged objects described by Coulomb's law
• Coulomb's law states the magnitude of the electric force ($F$) between two point charges ($q_1$ and $q_2$) is directly proportional to the product of their charges and inversely proportional to the square of the distance ($r$) between them
  • $F = k \frac{|q_1q_2|}{r^2}$, where $k$ is Coulomb's constant ($k = 8.99 \times 10^9 \frac{N \cdot m^2}{C^2}$)
  • Doubling the distance between charges reduces the force to one-fourth its original value
  • Tripling the charge on one object triples the force between them
• The direction of the electric force depends on the signs of the charges
  • Like charges repel each other, resulting in a force that points away from each other (two positive charges push away)
  • Unlike charges attract each other, resulting in a force that points toward each other (a positive and negative charge pull together)
• An electrostatic field is created by stationary electric charges, influencing the behavior of other charged particles in the vicinity

Properties of electric charge

• Quantization of charge
  • Electric charge is quantized exists in discrete units rather than continuously
  • The fundamental unit of charge is the charge of an electron or proton ($e = 1.602 \times 10^{-19} C$)
  • All charged objects have a charge that is an integer multiple of this fundamental unit (an object with a charge of $-3.204 \times 10^{-19} C$ has a charge equal to -2e)
• Conservation of charge
  • The total electric charge in an isolated system remains constant over time
  • Charge cannot be created or destroyed, only transferred between objects or converted between forms (rubbing a balloon on hair transfers electrons but does not create or destroy them)
  • In any process, the total charge before and after the process remains the same (the total charge of a system before and after a chemical reaction is equal)

Charge distribution and detection

• Electric dipoles consist of two equal and opposite charges separated by a small distance, often found in molecules
• Dielectrics are insulating materials that can be polarized by an external electric field
• An electroscope is a device used to detect the presence and type of electric charge on an object
• Grounding is the process of connecting an electrically charged object to the Earth to neutralize its charge