DC electricity Flashcards
What are converters?
Components that change electrical energy into useful energy
What is an electrical current
a movement of charged particles. In electrical circuits, the charged particles are usually electrons and they flow along conducting wires.
What is current?
The flow of coulombs
Coulombs are packets of electrons. One coulomb per second is called one Amp.
The current in a circuit is the energy transporter.
What is voltage of an energy source?
The number of joules of energy it supplies to each coulomb of the current that is flowing through it.
What happens when a current goes through a converter?
Energy is taken from each coulomb. The converter always takes the same amount of energy from each coulomb.
What is voltage of a converter?
The amount of energy taken per coulomb
What happens to each coulomb when it arrives at the energy source again?
When current flows around a closed loop, each coulomb gives up ALL the energy it took from the energy source to the converters in the loop. Each coulomb arrives back at the energy source “empty handed”. Each coulomb shares the energy it picked up from the energy source between all the converters it flows through.
What is power?
The rate (amount per second) at which energy is delivered.
Power equation with J and s
P = E/t
P = W E = J t = seconds
What is the relationship between power, current and voltage?
Coulombs deliver energy to the converters in a circuit in “packets”. The rate at which energy is delivered depends on:
- the number of coulombs passing through the converter per second (A)
- the size of the packets (V)
Power equation with I and V
P = IV
P = W I = A V = V
Which line is the positive and which line is the negative terminal?
The positive terminal is the longer vertical line.
What happens when a converter fails in a series circuit?
A series circuit has all the components connected in a single loop, so that whatever current goes through the energy source, the same current must go through all the energy converters. If one fails, the circuit loop will be broken and the current will stop flowing, so the other converters also stop operating.
What happens when a converter fails in a parallel circuit?
In a parallel circuit, after the current has gone through the energy source, it has a choice of two or more pathways (usually called branches) it can go round to get back to the source for more energy.
In a parallel circuit, each branch operates as if the other branches were not there. The battery supplies current to both lamps but the two current supplies are independent of each other. If one circuit was broken, the other lamp would just carry on as normal.
Advantage of connecting converters in parallel
If one fails and breaks the circuit branch, the other will keep operating as if nothing had happened.
Which direction does current enter the battery?
It enters the negative terminal and leaves the positive terminal.