How do I calculate electrical energy transferred?

AI Thread Summary
To calculate electrical energy transferred, use the formula Energy = Voltage * Charge. This is derived from the relationship between power, voltage, and current, where Power = Voltage * Current and Energy = Power * Time. Current can be expressed as Charge/Time, allowing for the simplification of Energy = Voltage * (Charge/Time) * Time, which results in Energy = Voltage * Charge. Understanding this relationship clarifies how voltage and charge relate to energy transfer. This explanation helps in grasping the fundamental concepts of electrical energy calculations.
Molly1235
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Can anyone tell me how to calculate electrical energy transferred when you are given a voltage and a charge? I'm really stuck as we haven't covered this before :-/
 
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Hopefully you recognise...

Power = Voltage * Current
and
Energy = Power * Time

So

Energy = Voltage * Current * Time

but

Current * Time = Charge

(Edit: or if you prefer Current = Charge/Time)

So

Energy = Voltage * Charge
 
CWatters said:
Hopefully you recognise...

Power = Voltage * Current
and
Energy = Power * Time

So

Energy = Voltage * Current * Time

but

Current * Time = Charge

(Edit: or if you prefer Current = Charge/Time)

So

Energy = Voltage * Charge

Ok, yeah I got as far as Energy = Voltage * current * time, but I'm afraid I don't understand how you got to energy = charge * voltage? (Probably being extremely dumb here...)
 
Ok so you got as far as ...

Energy = Voltage * Current * Time ...... (eqn 1)

Think about what current is. Current is the amount of charge flowing past a point per second. Just like the current of a river is the amount of water flowing past per second.

So the definition of current is Charge/Time

Now in equation 1 above you can replace "Current" with "Charge/Time" to give

Energy = Voltage * (Charge/Time) * Time

Time cancels to leave

Energy = Voltage * Charge
 
Oooh I understand now! Thank you very much!
 

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