Static Electricity and Electric Potential

Static Electricity and Electric Potential

by Ronnie Lorilla

Multiple Choice

Which is the ONLY subatomic particle that moves and is NOT located in the nucleus?

• Protons

• Electons

• Neutrons

Multiple Choice

Comparing: Which Law depends upon charge and distance between objects?

• Law of Gravity

• Coulomb's Law

• Both

Multiple Choice

Comparing: Which Law depends upon mass and distance between objects?

• Law of Gravity

• Coulomb's Law

• Both

Multiple Choice

What variable is a Coulomb the unit for?

• Charge

• Force

• Distance

• Mass

Multiple Choice

Which is the value of the constant in Coulomb's equation?

• k = 9·10^-9

• k = 9.8

• k = 6.67·10^-11

• k = 9 ·10⁹

Multiple Choice

The Electric Force is strongest when charges are...

• close together

• far apart

• the electric force is constant everywhere

Multiple Choice

When distance increases, electrostatic force ____________; we call this relationship ____________ proportional

• decreases;directly

• decreases;inversely

• increases;inversely

• increases;directly

Multiple Choice

A balloon is rubbed on a student's head. What occurs because of this?

• Charged particles on the balloon are destroyed

• Positively charged particles move from head to balloon

• Charged particles from the balloon are released into the air

• Negatively charged particles move from head to balloon

Multiple Choice

As two oppositely charged particles approach each other, what happens to the electrical force between them?

• The attractive force increases

• The magnitude of the electric force decreases

• The repulsive force increases

• The magnitude of their charges increases

Multiple Choice

A repulsive force exists between which two particles?

• Two neutrons

• An electron and a neutron

• An electron and a proton

• Two protons

Multiple Choice

Which two particles are attracted to each other?

• Two neutrons

• A proton and an electron

• Two protons

• An electron and a neutron

Electric Potential Difference

Electricity Explained

Electrical Circuits

The flow of charge through wires allows us to cook our food, light our homes, air-condition our work and living space, entertain us with movies and music and even allows us to drive to work or school safely

What is an Electric Field?

• The influnce of charge objects to move about in space.

  
  

• Vectors are arrows that describe the electric field

Electric Field Lines/Vectors

• Vectors/Arrows move away from the Positive Charges

• Vectors Always move toward the Negative Charges

Multiple Choice

What is an electric field vector?

• The direction a positive charge will move in an electric field

• the direction a negative charge will move in am electric field

• the space of the electric field

• the influence of the electric fiels

Electric fields are similar to gravitational fields

Both involve action-at-a-distance forces.

Multiple Choice

Potential Energy increases as it moves further from the source.

• Tue

• False

Multiple Choice

Potential energy increases as it moves further from the Neg (-).

• true

• false

Objects naturally move from high potential energy to low potential energy under the influence of the field force

• Work is required to move an object from low energy to high energy.

• To move a charge in an electric field against its natural direction of motion would require work

The movement of charge

• moves with the electric field

• High to Low

• Diagram A requires work to go from A-B

• Diagram B No work is required to go from B-A

Multiple Choice

Look at the image provided. Why does diagram B require work?

• the charge moves from low potential to high potential

• The charge moves from high potential to low potential

• the charge is unstable and requires energy to stabilize

• the electric field is in the opposite direction as the charge

Electric Potential in Circuits

• A battery powered electric circuit has locations of high and low potential

• An electric field established between the two terminals

• The charge would lose potential energy as moves through the external circuit from the positive terminal to the negative terminal

Multiple Choice

The quantity electric potential is defined as the amount of _____.

• electric potential energy

• force acting upon a charge

• potential energy per charge

• force per charge

As a positive test charge moves through the external circuit

• Each circuit element serves as an energy-transforming device

• Light bulbs, motors, and heating elements

Upon leaving the circuit element, the charge is less energized

• Location A high electric potential location

• Location C just after leaving the light bulb is a low electric potential location

• The loss in electric potential while passing through a circuit element is often referred to as a voltage drop

Electric Potential Difference

• the amount of potential energy per unit of charge at a specified location

• there is also a difference in electric potential between locations A and B

• This difference in electric potential is represented by the symbol ΔV

• One Volt is equivalent to one Joule per Coulomb

• V=J/C or C=V/J or J=C*V

​Calculating Potential Difference

​•Amount of potential difference:

•WORK DONE PER UNIT CHARGE

•1 VOLT = 1 J/C

​Electron-volts

​•Alternate unit for work/energy:

•Raises 1e to an electrical potential of 1 V

•1 eV = 1.6 x 10-19 J

Multiple Choice

As a proton moves in the direction the electric field lines...

• it is moving from low potential to high potential and gaining electric potential energy.
• it is moving from low potential to high potential and losing electric potential energy.
• it is moving from high potential to low potential and gaining electric potential energy.
• it is moving from high potential to low potential and losing electric potential energy.

Multiple Choice

Two protons are released from rest, with only the electrostatic force acting. Which of the following statements  is NOT true about them as they move apart? 

• Their electric potential energy keeps decreasing.
• Their electric potential energy keeps increasing.
• Their acceleration keeps decreasing.
• Their kinetic energy keeps increasing.

Multiple Choice

Which statements must be true about the surface of a charged conductor in which no charge is moving?

• The electric field is zero at the surface.
• The electric potential of the surface is zero.
• The electric potential is constant over the surface.
• The electric field is constant at the surface.