Physics: Electricity and Magnetism Flashcards

Comprehensive question-and-answer flashcards covering definitions, formulas, and concepts from the Physics notes on electricity, circuits, and magnetism.

What happens during the attraction of electric charges, and what potential energy is produced?

Unlike charges attract one another and give negative potential energy (attractive force).

What is charging by conduction?

Charging an object by allowing it to come into contact with an object that already has an electrical charge.

What occurs during charging by friction?

Two objects rub together and one becomes positively charged while the other becomes negatively charged.

How does charging by induction work?

Charging an object without direct contact (proximity to a nearby object charges a neutral object).

What are conductors?

Materials that allow electric charges to flow through them easily.

What is a coulomb?

The unit used to measure the quantity of electric charge.

How is current defined?

A flow of electricity through a conductor.

What is current electricity?

The continuous flow of electrons through a conductor.

What is direct current?

An electrical current that always moves in one direction.

What does an electric circuit consist of?

A voltage source and a continuous conducting path for a current to follow.

What is an electric current?

The flow of electric charge.

What is an electric field?

The field around charged particles that exerts a force on other charged particles.

What are electric field lines?

A map of an electric field representing the direction of the force that a positive charge would experience.

How is electric flux defined?

The product of a surface area and the component of the electric field perpendicular to the surface.

What is an electric generator?

A mechanical device that uses wire loops rotating in a magnetic field to generate electricity.

What is electric potential (aka potential difference)?

The difference in electrical charge between two points in a circuit expressed in volts.

What is electric potential energy?

Potential energy due to the position of a charge near other charges.

What are electrical conductors?

Materials that have electrons that are free to move throughout the material (for example, metals).

What is electrical energy?

A form of energy from electromagnetic interactions.

What is electrical force?

A fundamental force that results from the interaction of electrical charge.

What are electrical insulators?

Electrical nonconductors, or materials that obstruct the flow of electric current.

What is electrical resistance?

The property of opposing or reducing electric current.

What is an electrolyte?

A water solution of ionic substances that conducts an electric current.

What is an electromagnet?

A magnet formed by a solenoid that can be turned on and off by turning the current on and off.

What is the electromagnetic force?

One of four fundamental forces; the force of attraction or repulsion between two charged particles.

What is electromagnetic induction?

The process in which current is induced by moving a loop of wire in a magnetic field or by changing the magnetic field.

What is electron current and how does it flow?

The current opposite to conventional current; electron current flows from the negative terminal to the positive terminal.

What is electrostatic charge?

An accumulated electric charge on an object from a surplus or deficiency of electrons.

What is a magnetic dipole?

A magnet with two poles (North & South); all magnets are dipoles, and cutting one in half creates two dipoles.

What are magnetic field lines?

Invisible lines that map out the magnetic field around a magnet.

What is magnetic flux?

The lines of force surrounding a permanent magnet or a moving charged particle.

What are magnetic forces?

Forces that may attract or repel without touching.

What are examples of ferromagnetic materials?

Iron, cobalt, nickel.

What are magnetic poles?

The ends, or sides, of a magnet about which the force of magnetic attraction seems to be concentrated.

What is magnetic reversal?

The flipping of polarity of the earth's magnetic field.

How is magnetism defined?

The force of repulsion (pushing) or attraction (pulling) between poles of magnets.

How does a negative electric charge behave?

One of the two types of electric charge; it repels other negative charges and attracts positive charges.

What is an ohm?

The unit of resistance equivalent to volts/amps ($\text{volts}/\text{amps}$).

What does Ohm's Law state?

The law stating that resistance is equal to voltage divided by current ($R = \frac{V}{I}$).

How does a positive electric charge behave?

One of the two types of electric charge; it repels other positive charges and attracts negative charges.

What is power?

The rate of doing work.

What is the formula for the power dissipated by a resistor?

$$P = IV = I^2R = \frac{V^2}{R}$$

What happens during the repulsion of electric charges, and what potential energy is produced?

Like charges repel one another and give positive potential energy (repulsive force).

What is resistance, and how is it measured?

A material's opposition to the flow of electric current, measured in ohms.

What are resistors?

Objects that allow charge to flow at a reduced rate (change into heat or light).

What defines components connected in series?

An electrical connection of components in such a manner that current flows first through one and then through the other.

What is a simple circuit?

A circuit that has only one pathway for electricity to flow through.

What is a solenoid?

A cylindrical coil of wire that becomes electromagnetic when a current runs through it.

What are superconductors?

Materials in which, under certain conditions, the electrical resistance approaches zero.

What is a voltage drop?

The electric potential difference across a resistor or other part of a circuit that consumes power.