Kakaj Flashcards
What is current?
Current is the rate of flow of charge around a circuit
What is electric current?
A flow of charge round a circuit
What is voltage? ( potential difference)
Voltage is an electrical pressure giving a measure of the energy transferred
Whats the main electricity supply in peoples homes?
Alternating current - it reverses is direction back and forth.
What is an alternating current? (A.c)
An alternating current is a wave/ wiggly
What can the CRO show?
CRO can show current as a trace on a graph
What direction does direct current go in? (D.c)
Direct current always flows in the same direction
The CRO trace is a ……?
Horizontal line
What do you get direct current from?
Batteries and solar cells
What are electrons?
Negatively charged particles
What is electrical power?
Electrical power is the energy transferred per second
What are the units of power?
Watts (W)
If you measure the current and voltage what can you tell?
The power.
What does a voltmeter do?
Measures the voltage across the component
Whats the formula for calculating the power of the component?
Power= current x voltage
(watts). (Amps). (Volts)
W. A. V
I
How do you work out voltage?
Power divided by current
P. I.
What is electromagnetic induction?
Creating a voltage and maybe a current in a conductor by moving a magnet in or near a coil of wire.
If you want a bigger peak voltage ( and current) you have to increase what?
One of these four things; 1- the strength of the the magnet 2- the area of the coil 3- the number of turns on the coil 4- the speed of the movement
How do generators work?
By rotating a magnet or a coil of wire.
What is non- renewable energy?
Energy that will run out one day.
What are the Non- renewable energy resources?
1- coal
2- oil
3- natural gas
4- nuclear fuels
What do power stations use to drive a turbine?
Steam
Renewable energy resources will never run out. True or false?
True
What does hydroelectric power usually involves?
Flooding a valley by building a bid dam.
