Electricity

Static Electricity

Electricity caused by the accumulation of excess charge on an object.

What is a spark and lightning bolt similar to?

Both are sudden discharges of static electricity, where electrons rapidly move to balance charge differences.

Electrostatic series

A ranking of materials based on their tendency to gain or lose electrons.

Conductors

Materials that allow free movement of electrons (e.g., metals).

Insulators

Materials that resist electron flow (e.g., rubber, plastic).

Charge separation

Occurs when charged objects induce a redistribution of charges in neutral objects.

Grounding

Process that allows excess charge to flow into the Earth, neutralizing charged objects.

Induction charging

Charging an object without direct contact by bringing a charged object near.

Friction charging

Charging that occurs by rubbing two materials together.

Contact charging

Charging that occurs when a charged object touches a neutral object.

Current

Flow of electric charge measured in amperes.

Potential difference (Voltage)

Energy per unit charge, measured in volts.

Resistance

Opposition to current flow, measured in ohms.

Ammeter

Instrument used to measure electric current.

Voltmeter

Instrument used to measure potential difference (voltage).

Battery

Source of electrical energy.

Fuse

Device that protects circuits by breaking current when it exceeds a certain level.

What happens when connecting a voltmeter?

It is connected in parallel across a bulb to measure potential difference.

Why use insulators for wires?

To prevent current leakage and protect against electric shock.

How does a circuit breaker work?

It interrupts current flow during an overload or short circuit to prevent damage.

Connecting cells in series

This produces the highest electrical potential.

Total potential from five 1.8V cells in series

Total potential = 1.8V × 5 = 9.0V.

Advantages of series circuits

Increases voltage.

Advantages of parallel circuits

Increases current and ensures function if one cell fails.

Brightest bulb in a parallel circuit

Has the fewest bulbs.

Effect of a burned-out bulb in parallel

Other bulbs remain unaffected.

Adding bulbs to a parallel circuit

Decreases intensity due to increased resistance.