Physics - Electricity

 

Voltage

A voltage is essential to get electrons (and/or charges in general) moving. Movement of charges can take place in a wire ( the most familiar place where electrons move), in a solution containing ions (inside a chemical cell) , in a molten ionic solid (like sodium chloride (where electrolysis is used to produce chlorine gas) or even in air (in the case of lightning , for instance).

A voltage can be produced in various ways (concept map below). The most common are electromagnetic induction (which takes place in power stations) and electrochemistry (batteries).

 

Concept map illustrating how different forms of energy can be converted into electrical energy, via different devices and physical phenomena

 

Some examples of voltages on the table below:

System
Typical voltage
Human nervous system
70mV
Mains voltage
230V or 110V
Electric fish
100 to 600V
Sparks from synthetic wool jumper
1 kV
Lightning
10 to 100MV
AA battery
1.5V
   

 

 


Electricity Index