Electric Circuits & Forces – Key Vocabulary

30 vocabulary flashcards summarizing core terms and definitions from the lecture on electric circuits and forces.

Parallel circuit

A circuit with multiple branches where the voltage is the same across every branch but current splits between them.

Series circuit

A circuit with a singular path; the current is identical everywhere, but voltage divides across components.

Branch (in circuits)

An individual path in a parallel circuit containing one or more components through which current can flow.

Current (I)

The flow of electric charge per second, measured in amperes, detected with an ammeter.

Voltage (V)

The amount of energy the electrons have. Stays equal across branches in parallel circuits and divides in series circuits.

Ohm’s Law

The relationship V = I x R, showing how voltage, current, and resistance are connected.

Resistance (R)

Opposition to current flow; greater resistance lowers current and causes a larger voltage drop.

Wire resistance (length effect)

Longer wires have higher resistance because electrons encounter more material.

Wire resistance (width effect)

Wider wires have lower resistance, giving electrons more paths to move through.

Light-bulb brightness in series

Adding bulbs makes each dimmer because voltage is shared among them.

Light-bulb brightness in parallel

Adding bulbs keeps brightness unchanged because each branch receives full supply voltage.

Switch in a parallel circuit

A control that opens or closes only its own branch without affecting others.

Force

A push or pull that can change an object's shape, speed, or direction; measured in newtons.

Push

A force directed away from the source (e.g., hitting a ball).

Pull

A force directed toward the source (e.g., towing a car).

Newton (unit)

The SI unit of force, measured with a force meter; arrow length often represents its size and direction.

Balanced forces

Equal and opposite forces that cancel, causing no change in motion.

Unbalanced forces

Forces that are not equal, resulting in acceleration or change in motion.

Newton’s First Law

Newton’s First Law states: An object remains in its state of motion unless acted on by an unbalanced force

Newton’s Second Law

Newton’s Second Law states: The acceleration of an object depends on its mass and the net force acting on it.
Force = Mass x Acceleration

Newton’s Third Law

Newton’s Third Law states: For every action force there is an equal and opposite reaction force.

Air resistance

A frictional force exerted by air that opposes the motion of objects through it.

Gravity

Attractive force between masses that pulls objects toward each other (e.g., toward Earth).

Electrostatic force

Force between electrically charged objects, either attractive or repulsive.

Tension

Pulling force transmitted through a rope, string, or cable.

Compression

Pushing (squashing) force that shortens or squeezes a material.

Friction

Force that resists motion between two contacting surfaces.

Thrust

Forward-directed push that propels an object, such as a rocket or airplane.

Buoyancy

Upward force exerted by a fluid on an immersed object.

Magnetic force

Attraction or repulsion between magnetic materials or moving charges.

Support Force

The upward force that balances the weight of an object resting on a surface, preventing it from falling.