Physics FInal

• Uncharged conducting sphere


  Becomes positively charged if brought in contact with a highly positive body
• Electric lines of force


  Start from positive charges and end on negative charges
• The number of protons is equal to the number of electrons in an electrically neutral atom
• The charge of an object is an integral multiple of the charge of an electron if the charge is quantized
• When static conditions are reached, the charge on a conductor resides on its surface. This statement explains Gauss's Law and that the electric field inside the conductor is parallel to the surface.
• Gravitational force and electric force


  • The main difference is that gravitational force is always attractive
• When an electron is moving in an electric field


  The direction of the acceleration is opposite the field direction
• Quarks


  Particles that have fractional charges of an electron
• The figure shows that Q1 is positive, Q2 is negative, and Q3 is positive
• Farad


  The SI unit of capacitance
• Volt/meter


  Equivalent to newton/coulomb
• Zero


  The value of the electric potential energy at an infinite distance from a point charge
• Robert Andrews Milikan determined the charge of an electron
• Cell


  Considered a capacitor with the cell membrane as the dielectric
• Volt


  A unit of potential
• Electric lines of force and equipotential surfaces are always perpendicular to each other
• If both the diameter of a wire and its length are quadrupled


  It decreases to one-fourth its original value
• Water is a conductor
• Labeling a circuit breaker is a good practice in handling electricity
• The figure shows the correct way of measuring the total current and the voltage across the resistor
• Household circuitry is prevented from overloading by means of a fuse
• Andre Marie Ampere is considered the Isaac Newton of electrodynamics
• Conventional current


  The flow of positive charges per unit time
• Drift velocity of electrons


  • It is proportional to the electric field
  • It is proportional to the current density
  • Its direction is opposite to that of the electric field