Electricity and Magnetism Flashcards
What is static electricity? (2) Give an example. (2) (Any good example)
Static electricity is a build-up of electrical charge on an object, which can be either positive or negative.
A photocopy machine is a static electricity example. It uses electrostatic force; the detailed images get imprinted on the paper through a drum consisting of positive charges, whereas the ink has negative charges. Drum and paper will rub against each other to create an imprint on the paper.
What is current electricity? (1)
An electric current is a flow of charged particles.
Are the flow of conventional current and the flow of electrons opposite or the same? (1)
Opposite.
Distinguish between an electrical conductor and an electrical insulator. (2)
Conductors are materials which allow electrical current to flow through them easily. Metals are generally good electrical conductors.
Insulators are materials which are poor conductors and do not allow electrical current to flow through them easily.
Identify the common circuit symbols. (2) (Mark yourself)
https://www.bbc.co.uk/bitesize/guides/zgvq4qt/revision/1
Compare series and parallel circuits. (2) (Mark yourself)
https://www.bbc.co.uk/bitesize/guides/z437hyc/revision/1
Define voltage and state its units. (2)
Voltage is the potential difference across a cell, electrical supply or electrical component. It is measured in volts (V).
Define current and state its units. (2)
Moving electric charges, eg electrons moving through a metal wire. The unit of current is the Ampere, e.g. the current in the bulb is 4 amps or amperes (A).
Define resistance and state its units. (2) Do conductors have relatively low or high resistances compared to insulators? (1)
Resistance is the opposition in an electrical component to the movement of electrical charge through it. Resistance is measured in ohms.
Conductors have relatively low resistances compared to insulators.
What is a LDR and how does it works in a circuit, in low or in strong light? (2)
A Light Dependent Resistor is a type of resistor which is affected by changes in light levels. A cadmium sulphide layer causes a decrease in resistance in the light and increase in the dark.
Will charge always take the hardest or easiest route? (1)
Easiest.
What is a diode? (2)
A diode is an electronic component that will only allow electric current to pass through it in one direction.
What is an LED? (2) How does it work, in simple terms? (2)
A type of diode that emits light when a current goes through it in a certain direction. (Electrons go from one side of the material to the other and emit light when they get there.)
What is the role of switches and how do you fill in a ‘truth table’. (2)
Switches enable you to turn an electric curcuit on and off. To fill in a truth table put the different switches on both the horizontal and vertical axis. Then record the outputs when you open and close the switches.
Describe some common properties of magnets. (3)
The region around a magnet where a force can be felt is called the magnetic field. If magnetic materials enter this region, they will be attracted to the magnet.
One of the most important features of a permanent magnet, whatever shape it is, is that it has two different ends. These ends are called poles. There is a north (N) pole and a south (S) pole.
If you break a magnet in two, each half will still have two poles - north and south.
