science electricity and magnetism Flashcards
explain how objects can become charged.
objects can be charged positively or negatively by transferring electrons.
describe how charged objects interact.
like charges repel and unlike charges attract.
Describe what is meant by current, potential difference and resistance.
Describe how to measure current and potential difference.
Electric current is the amount of charging flowing per second. you measure current in amps(A) using an ammeter.
The potential difference of a cell tells you the size of the push on the charges and how much energy can be transferred by them. You measure it in volts(V) using a voltmeter.
Describe the difference between series and parallel circuits.
series circuits contain only one loop, and the current is the same everywhere. Parallel circuits have branches and the currents in all the branches add up to make the total current.
Calculate the resistance of a component and or a circuit.
a component with a high resistance has a small current through it. resistance is measured in ohms. you calculate the resistance using the poteintial difference across a component and the current through it
Describe the difference between conductors and insulators in terms of resistance.
insulators have a very high resistance and conductors have a very have a very low resistance.
Describe how magnets interact.
magnets have a north and south pole like poles repel and unlike poles attract.
Describe how to represent magnetic fields.
magtnetic materials feel a force in the region around a magnet called a magnetic fiels. magnetic field lines show the pattern of the magnetic firld.
Describe how to make an electromagnet.
a current flowing in a coil wire wrapped around a magnetic materisl is a electromagnet.
Describe how to change the strength of an electromagnet.
add more coils to make it stronger and take some away to make it weaker.
Describe some uses of electromagnets.
maglevf trains, hospitals, cars.
