10.6 Electric Charges and Fields

• The total amount of electric charge in the universe is conserved.


  True
• Electric field lines start from positive charges and end on negative charges.

  True
• Electric field lines for a negative charge point inward
• Which type of charge attracts negative charges?

  Positive charge
• Match the charge type with its interaction with other charges:

  Positive charge ↔️ Attracts negative, repels positive

  Negative charge ↔️ Attracts positive, repels negative
• Electric field lines start from positive charges and end on negative charges.


  True
• Electric field lines never cross
• Gauss's Law states that the total electric flux through a closed surface is proportional to the enclosed charge
• Gauss's Law requires symmetry in charge distribution
• The Gaussian surface inside a charged cylinder is a cylinder
• What is the mathematical expression for Gauss's Law?

  $∮ E ⋅ dA =$$Qₑₙ / ε₀$
• How does Gauss's Law compare to Coulomb's Law in terms of symmetry requirements?

  Requires symmetry
• There are three types of electric charges: positive, negative, and neutral.

  False
• When rubbing a plastic comb against hair, electrons transfer from the hair to the comb
• Electric field lines start from positive charges and end on negative charges
• The density of electric field lines indicates the strength of the electric field.
• Electric field lines start from positive charges and end on negative
• The strength of an electric field is defined as the force per unit charge
• A test charge of 2C experiences a force of 10N. What is the electric field strength?

  5 N/C
• What is the electric field strength outside a uniformly charged sphere of radius R and charge Q?

  Q / (4πε₀r²)</latex>
• An electric dipole consists of two equal and opposite charges separated by a small distance
• The electric field strength around a dipole is inversely proportional to the square of the distance from the dipole.


  True
• Match the type of electric charge with its properties:

  Positive Charge ↔️ Carried by protons

  Negative Charge ↔️ Carried by electrons
• Order the properties of electric field lines:

  1️⃣ Start from positive charges

  2️⃣ End on negative charges

  3️⃣ Density indicates field strength
• Electric field lines start from positive charges and end on negative charges.


  True
• Electric field lines never cross
• The total electric charge in the universe is conserved
• What is visualized using electric field lines?

  Electric field
• The electric field strength is calculated using the formula E = F/q
• The electric field strength is measured in Newtons per Coulomb (N/C).


  True
• What is the mathematical expression for Gauss's Law?

  \oint E \cdot dA = \frac{Q_{\text{enc}}}{\varepsilon_{0}}\</latex>
• The Gaussian surface for a charged sphere outside its radius is a sphere.

  True
• The electric field inside a uniformly charged solid cylinder increases linearly with radius.

  True
• Gauss's Law is more complex to use for symmetrical systems than Coulomb's Law.

  False
• What is the electric field inside a uniformly charged solid cylinder with charge density ρ?

  $E =$$ρr / (2ε₀)$
• What particle carries a positive charge?

  Protons
• Match the property with the type of charge:

  Positive Charge ↔️ Attracts negative, repels positive

  Negative Charge ↔️ Attracts positive, repels negative

  Conservation ↔️ Total charge is conserved
• Electric field lines can cross each other.

  False
• Match the characteristic of electric field lines with its description:

  Direction ↔️ Starts from positive, ends on negative

  Density ↔️ More dense lines indicate stronger field

  Crossing ↔️ Lines do not cross each other
• Electric field lines can cross each other.

  False