p10 Flashcards
what is the difference between a series circuit and a parallel circuit?
series circuit have one loop the current to flow around, in parallel circuits the junctions that allow the circuit to take different routes
how is a voltmeter connected into a circuit?
in parallel
what does a voltmeter measure?
potential difference voltage
what is the unit for potential difference?
volts
how is an ammeter connected in the circuit
in a series
what does an ammeter measure?
current
what is electric circuit?
The rate of flow of charge
what happens when there is a source of potential difference in the closeted circuit?
there will be a current in the circuit
if the resistance in a circuit increases, what happens to the current?
it decreases
if the resistance in a circuit decreases, what will happen to the current?
increases
how can resistant be changed in a circuit?
putting different resistors in a circuit or by using a variable resistor
Why does current decrease when resistors are connected in a series?
The password becomes harder for the current to flow through
what happens to the net resistance if two resistors are connected in parallel
it decreases
why does current increase when resistors are connected in parallel?
there are now more paths for the current
what happens to the resistance of an LDR when light intensity increases
it decreases
what happens to the resistance of a transmitter when temperature increases?
it decreases
what is true when there is an electric current and a resistor
there is an energy transfer, which heats the resistor
what happens when an electrical current does work against the electrical resistance?
electrical energy is dissipated as thermal energy in the surroundings
what causes thermal energy in circuits
collisions between electrons and the ion in the lattice
what is power?
The energy transferred per second
what is the power transfer in any circuit device related to?
The potential difference across it and the current in it
what is direct current?
movement of charge in One Direction are you?
give a source of direct current
cells and batteries
what is alternating-current?
current where movement of charge changes direction
what sort of current is the domestic supply in the UK?
a. c
what is the frequency of the UK domestic electricity supply?
50Hz
what is the potential difference in the UK domestic electricity supply?
abt 230V
what is the function of the live wire?
connects the appliance to the generators at the power station
what is the function of the natural wire
it is the return path to the power station
what is the function of the Earth wire?
for safety
what should the potential difference be of the live wire?
230v
what should the potential difference of the natural be
0v
What’s the potential difference of the Earth wire be
0V
To which wire should switches and fuses be connected in a domestic circuit
live
how fuses work?
if the current is too high, the wire inside the fuse will melt breaking the circuit
how to circuit breakers work?
it detects a change in current and safety switch on the supply
what colour is the live wire?
brown
what colour is the natural wire
blue
what colour is the Earth wire?
yellow and green stripes
