Electric Current and Electron Flow

What happens to free electrons in a metal wire when there is no electric potential difference across it?

• A) They move in a straight line.
  

• B) They remain stationary.
  

• C) They move randomly due to thermal energy.
  

• D) They move in a circular path.

Why does a lamp turn on almost instantly when a light switch is flipped, even though electron drift speed is very slow?

• A) The electric field propagates through the circuit almost instantly.
  

• B) The electrons move at the speed of light.
  

• C) The switch directly sends energy to the bulb.
  

• D) New electrons are generated at the lamp instantly.

What is the primary function of an electric field in a circuit?

• A) To create resistance.
  

• B) To push electrons, initiating current flow.
  

• C) To convert electrical energy into thermal energy.
  

• D) To slow down the movement of free electrons.

What is the role of free electrons in a conductor?

• A) They remain stationary and store energy.
  

• B) They transfer electrical energy by colliding with atoms.
  

• C) They are responsible for the movement of protons.
  

• D) They generate an electric field.

Which of the following best describes the drift speed of electrons in a typical household circuit?

• A. Very fast, close to the speed of light
  

• B. Moderate, around 1 meter per second
  

• C. Slow, only a few centimeters per hour

• D. Completely stationary

When you close a switch in a circuit, what actually starts the flow of electrons?

• A. The battery’s stored electrons are injected into the circuit
  

• B. The electric field that forms within the wire
  

• C. Thermal energy in the wire
  

• D. A chemical reaction on the lamp’s filament

What is the primary reason electrons in a conductor have such a slow drift velocity?

• A. They are massive and move slowly under any force
  

• B. They constantly collide with the atoms in the conductor
  

• C. They have no electric charge
  

• D. They move in a vacuum with no interactions