Electricity And Magnetism Flashcards
(30 cards)
What is static electricity?
Static electricity occurs when there is an imbalance of electric charges caused by the transfer of electrons between objects.
What happens to positive and negative charges?
- Positive charges repel other positive charges * Positive charges attract negative charges * Negative charges repel other negative charges * Negative charges attract positive charges
What are the components of an atom?
- Protons (positive charge) * Electrons (negative charge) * Neutrons (no charge)
How does static electricity work?
Electrons move from one object to another when rubbed together, causing one object to become negatively charged.
Define charge.
Property of matter (protons + electrons).
What is electric current?
Electric current is the flow of electric charge around a circuit, typically measured in amperes (A).
How is current measured?
Use an ammeter to measure current in amperes (A).
What causes electric current?
The battery or cell provides the potential difference (voltage) that pushes the electrons around the circuit.
What is a series circuit?
A series circuit has all components connected in a single loop where the current is the same everywhere.
What is a parallel circuit?
A parallel circuit has components connected in separate branches, causing the current to split across each branch.
What is potential difference (P.D.)?
P.D. is the force pushing electric charges through a circuit, indicating how much energy is transferred to components.
How is potential difference measured?
Use a voltmeter to measure potential difference in volts (V).
Define resistance.
A measure of how much a component resists the flow of electric current, measured in ohms (Ω).
What are conductors?
Materials that allow electricity to flow through easily (e.g., metals like copper and iron).
What are insulators?
Materials that do not allow electricity to flow (e.g., rubber, plastic).
How does resistance depend on wire properties?
Resistance depends on the material and the length of the wire; longer wires have higher resistance.
What are the magnetic poles?
Every magnet has a north pole and a south pole; like poles repel and opposite poles attract.
How can magnetic fields be represented?
Magnetic fields can be represented using field lines that go from the north pole to the south pole.
What happens when a wire carries electric current?
A wire carrying an electric current creates a magnetic field around it.
What is an electromagnet?
An electromagnet is created by passing a current through a coil of wire, often with a magnetic material as the core.
What factors affect the strength of an electromagnet?
- Number of loops (more loops = stronger field) * Current (more current = stronger field) * Core material (iron is common)
What are some uses of electromagnets?
- Magnetic Levitation (Maglev Trains) * Sorting metals in scrapyards * Relays
What is a simple motor?
A basic motor uses two magnets and a coil of wire; current flowing through the coil creates an electromagnet that spins.
What is true about current in series circuits?
Current is the same everywhere.
