How do I calculate electrical energy transferred?

In summary, to calculate electrical energy transferred when given a voltage and a charge, you can use the formula Energy = Voltage * Charge. This is derived from the equations Power = Voltage * Current and Energy = Power * Time, and the definition of current as Charge/Time. By replacing Current with Charge/Time in the equation for Energy, we can simplify it to Energy = Voltage * Charge.
  • #1
Molly1235
77
4
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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  • #2
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
 
  • #3
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...)
 
  • #4
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
 
  • #5
Oooh I understand now! Thank you very much!
 

1. What is electrical energy transferred?

Electrical energy transferred refers to the movement of energy from one location to another through the flow of electric charge. It is a measure of the amount of energy that is transferred from a power source to a consumer.

2. How is electrical energy transferred?

Electrical energy is transferred through the use of conductors, which are materials that allow the flow of electric charge. The transfer occurs when an electric current is passed through the conductor, causing the movement of electrons and the conversion of electrical energy into other forms of energy, such as heat or light.

3. What are some examples of electrical energy transfer?

Some common examples of electrical energy transfer include the charging of a battery, the use of a light bulb, and the operation of electronic devices such as computers and cell phones. Electrical energy is also transferred through power lines to provide electricity to homes and buildings.

4. What factors affect the amount of electrical energy transferred?

The amount of electrical energy transferred depends on the voltage and current of the system. Voltage is the measure of the electric potential difference between two points, while current is the measure of the flow of electric charge. Additionally, the resistance of the conductor and the duration of the transfer also play a role in determining the amount of energy transferred.

5. How is electrical energy transferred measured?

The SI unit for measuring electrical energy transferred is the watt (W). This unit is a measure of power, which is the rate at which energy is transferred. Electrical energy transferred can also be measured in joules (J), which is the unit for energy, by multiplying the power (watts) by the time (seconds) during which the energy is transferred.

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