5.1 Alternating current Flashcards
What is direct current
current goes in one direction only
Where is direct current supplied
by batteries
Where is alternating current supplied
the mains
What is alternating current
Current reverses direction very rapidly
How can alternating current work
The voltage switches between positive and negative values
What is the voltage of the UK
230V
What is the frequency of the mains in the UK
50Hz
What is frequency
The amount of times the current changes direction every second
What is the main benefit of using AC instead of DC
Very easy to use a transformer to increase or decrease the potential difference
Name appliances that use direct current
Phone, Laptop, Ipod
In alternating current what happens to the height if the potential difference of the supply increases
the height increases
In alternating current what happens if the frequency of the supply increases
peaks would be closer together
Whats the equation for power
voltage x current
What does a step up transformer do
increases voltage
decreases current
what does a step down transformer do
decreases voltage
increases current
Why is it beneficial to transmit electricity through cables to our homes at a high pd
Dont lose any energy, the higher the current more energy is lost
Why is the potential difference very high for the national grid
less current needed to transfer the same amount of power, so the power loss due to the resistance heating up the cable is reduced. more efficient way to transfer power
Why is the potential difference reduced before it is supplied into our homes
dangerous, blow appliances
Why is the grids potential difference very large
Less current, so the power loss due to the resistance heating in the cables is reduced. The National Grid is very efficient
