Revise: Electrical charge carriersCurrent, charge and time
Electrical current is electrical charge transferred in a particular time. These three properties can be calculated using the equation Q=It. Current can be a.c. or d.c.
Electrical current is defined by how much electric charge has been transferred per second, giving the following relationshipA relationship tells us how two or more variables work together, eg the relationship between resistance, voltage and current is: resistance = voltage ÷ current.:
\(current=\frac{charge}{time}\)
Rearranging this we get:
\(charge = current \times time\)
The symbol for charge is \(Q\), it is measured in coulombs (\(C\)).
The symbol for current is \(I\), it is measured in amperes (\(A\)).
The symbol for time is \(t\), it is measured in seconds (\(s\)).
This gives the relationship:
\(Q = I \times t\)
Example
Question
Calculate the charge that passes through a lamp in 2 minutes if the current is \(1.5A\)?
To calculate the charge, you need to use the following relationship:
\(charge = current \times time\)
Remember to convert minutes into seconds by multiplying by 60
