Electric Potential

• What is the definition of electric potential for a point charge?

  The work done per unit charge
• How is electric potential measured?

  In J C or V
• What type of quantity is electric potential?

  It is a scalar quantity
• What does the sign of electric potential indicate?

  The sign of the charge
• Where does electric potential have a value of zero?

  At infinity
• What factors does electric potential at a point depend on?

  The magnitude of the charge and distance
• What is the behavior of electric potential around a positive charge?

  • Positive value
  • Increases when moving closer
  • Decreases when moving away
  • Decreases in the direction of repulsion
• What is the behavior of electric potential around a negative charge?

  • Negative value
  • Decreases when moving closer
  • Increases when moving away
  • Decreases in the direction of attraction
• What is the formula for electric potential around a point charge?

  V = $\frac{Q}{4\pi\epsilon_0 r}$
• What does the electric potential do as the distance from a positive charge decreases?

  It increases

  
• What happens to energy when a positive test charge moves closer to a positive charge?

  Energy must be supplied

  
• What happens to electric potential as the distance from a negative charge increases?

  It decreases

  
• How does electric potential relate to distance?

  It has an inversely proportional relationship

  
• How does the sign of electric potential compare to gravitational potential?

  Electric potential can be positive or negative
• How do you combine electric potentials from multiple charges?

  • Add each potential together
  • Use the formula:

  $V =$$\frac{Q_1}{4\pi\epsilon_0 r_1} +$$\frac{Q_2}{4\pi\epsilon_0 r_2}$
• What is the combined potential at a point caused by two equal positive charges?

  It is double the potential of one charge
• What is the potential of the Van de Graaff generator's dome?

  240 kV
• How do you calculate the charge stored on the dome?

  Use $Q =$$4\pi\epsilon_0rV$
• What is the distance from the center of the dome to calculate potential at 30 cm from the surface?

  0.45 m
• What is the final potential at a distance of 30 cm from the dome's surface?

  80 kV
• What are the steps to calculate the charge stored on the dome?

  1. List known quantities
  2. Use the formula:

  $Q =$$4\pi\epsilon_0rV$

  1. Substitute values to find Q
• What are the steps to calculate the potential at a distance from the dome?

  1. Determine total distance from center
  2. Use the formula:

  $V =$$\frac{Q}{4\pi\epsilon_0r}$

  1. Substitute values to find V