Exam Topic 1 - Electricity Flashcards
Conductors
Delocalised atoms in substances that are free between atoms.
Parallel circuit formula
Calculated by adding up the reciprocals of the resistance valves and then taking the reciprocal of the total. (R=(1/R+1/R2+1/R3).
Are atoms positive or negative?
Positive
What happens when the electrons can jump across a gap to equalise the charge?
All of the energy stored in the electrons converts to heat, light, sound and kinetic energy (movement).
What is the unit used to measure current?
Ampere (A)
Current electricity
The movement of charge/electrons through an electrical circuit
What does static electricity rely on?
Stationary electrons
Electric current
The movement of charge on an electrical circuit.
What are the two types of current electricity and what are they?
Direct current (DC) - One direction, Alternating current (AC) - Alternating directions
What does an ammeter measure
The amount of charge that flows through it every second
What pushes the electrons on a wire?
Battery
Do positive or negative charges move?
Negative charges move, positive don’t.
What do you use to measure resistence?
Multimeter.
What is the unit for resistence?
Ohms
Are electrons positive or negative?
Negative
Static Electricity
The build up of charge on a surface
What does a high or low resistence mean?
A high resistence means that it is difficult for electrons to pass through a material a low resistence means the opposite
Insulators
Electrons stuck in rigid positions
Series circuit
All components on the same pathway
Symbol for current
I
Unit for voltage
Volts
Parallel circuit
an electrical path that branches so that the current divides and only part of it flows through any branch
Another way to describe voltage?
The energy needed to move a unit charge to flow between two points
Resistence
When electrons pass along the wires of an electric current their path is restricted a little by the atoms that make up the wires
What happens if a charge becomes to great?
The electrons can jump across a gap to equalise the charge.
What instrument is used to measure current?
Ammeter
What does resistance depend on?
Type of material, length of wire, thickness of wire, temperature of wire.
What is ohm’s law
Current = Volts/resistence
Parallel circuit
All components not on the same pathway
Voltage
Potential energy in the circuit
Series Circuit
All components have the same current through them but we split the voltage between them.
What is the total resistence of a series circuit + formula
Equal to each of the resistences added together (R = R1+R2+R3).
What is the release of energy
Spark
