Electricity 1

What is electrostatics?

The study of stationary electric charges and their interactions.

How is static electricity created?

By friction transferring electrons between insulating materials.

What happens when electrons are gained?

The object becomes negatively charged.

What happens when electrons are lost?

The object becomes positively charged.

What is the rule for electric charge interaction?

Like charges repel; opposite charges attract.

Name one use of static electricity.

Spray painting for even coating.

Name one danger of static electricity.

Sparks that can cause explosions in fuel vapours.

What is an electric field?

The region around a charged object where it exerts a force on another charge.

What do electric field lines show?

Direction of force; away from positive, toward negative.

What does closeness of electric field lines indicate?

Stronger electric field.

What is current (I)?

In an electric circuit, current is the flow of electrons, measured in Amperes (A).

What is voltage (V)?

The voltage is a measure of how big of a push the electrons are given as they leave the cell or battery.

What is resistance (R)?

The opposition to the flow of current, measured in Ohms (Ω).

What is the equation for charge flow?

Q = I × t

What is the equation for Ohm’s Law?

V = I × R

What does Ohm’s Law state?

Current is directly proportional to voltage across a resistor at constant temperature.

What kind of graph does an ohmic conductor have?

A straight line through the origin (linear I–V graph).

What is the total resistance in a series circuit?

R_total = R₁ + R₂ + R₃ …

What is the current like in a series circuit?

Same throughout the circuit.

How is voltage shared in a series circuit?

Divided between components.

What is the total resistance in a parallel circuit?

1/R_total = 1/R₁ + 1/R₂ + …

How is voltage shared in a parallel circuit?

Same across all branches.

How is current shared in a parallel circuit?

Split between branches depending on resistance.

What happens to total resistance when you add resistors in parallel?

It decreases.

What factors affect the resistance of a wire?

Length, thickness, material, and temperature.

How does length affect wire resistance?

Longer wire = greater resistance.

What is the I–V graph shape for a filament bulb?

Curved – resistance increases with temperature.

Why does a filament bulb's resistance increase?

Wire heats up as current increases.

What is one advantage of parallel circuits over series circuits?

Each component gets full voltage and can operate independently.

What happens to other components if one fails in a series circuit?

All stop working.

What is the equation for power using voltage and current?

P = V × I

What is the equation for energy using charge and voltage?

E = Q × V