Mains electricity

Why does the National Grid use a very high potential difference of around 400,000V?

How is the potential difference from a power station (25,000V) increased to 400,000V through the power lines?

In ac supplies, the current is constantly changing direction.

Calculate the power of a hairdryer carrying a current of 5A if it has a resistance of 40Ω:

How many Hertz (cycles per second) is the frequency of the ac mains supply?

You can also find the power if you don't know the potential difference, using the equation P = I²R

Which definition of potential difference is correct?

Which is the correct equation linking Current to potential difference and Power?

What are the two types of electricity supply?

Which wire is at zero Volts and carries current out of an appliance, when it is working normally?

The Uk mains supply is an ac supply at around how many Volts?

Which wire does not carry any current unless the appliance is faulty?

Which of the energy transfers from the chemical energy store in a handheld electric fan's battery is correct?

The neutral wire is at 0V potential difference

The amount of energy transferred by electrical work is given by:

Which is the correct equation linking potential difference to energy and charge?

Calculate the energy transferred through the 3V battery in this toothbrush when it transfers 140 Coulombs of charge:

What is the national grid?

Cells and batteries can only supply direct current (dc) that is always flowing in the same direction

An electric iron transfers 6000 J of energy in 30 seconds. Calculate its power.

Even if an appliance is turned off, there is still a danger of electric shock

Calculate the energy transferred when 10,000C of charge passes from a 200V source:

Why does a moving charge transfer energy?

3-Core cables have three wires inside them, which combination of names and colours is correct?

When does maximum demand for electrical power occur?