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Electricity

Parallel Circuits

What is the Current in a Parallel Circuit?

1. In a parallel circuit the current depends on the
resistance of the branch (see the calculation below).

2. The total current flowing in to the branches is
equal to the total current flowing out of the branches.
In the circuit diagram below A1 = A5

How to Calculate the Current in a Parallel Circuit.

The current at A2 flowing through the 2 ohm resistor
can be found using the equation V = I x R.

The equation can be rearranged to give
current = voltage ÷ r
esistance    I = V ÷ R

If the supply voltage is 12 volts,

I = V ÷ R

= 12 ÷ 2

= 6 amps.

See the next page for how to calculate the current in
the other two resistors and the total current in the circuit.

You would get the same answer for the current in
the 2 ohm resistor, whether or not the other resistors
are connected in the circuit. For the parallel circuit
above, each component behaves as if it is
connected on its own to the cell, and is unaware of the
other components. See lamps in a parallel circuit
.

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