### Finding Current in a Series Circuit

- In a series circuit, the current flow through each of the resistor is equal to the current flows through the whole circuit.
- Potential difference (V) across the whole circuit is equal to the e.m.f. (E) if the internal resistance is ignored.
- Effective resistance for the whole circuit = R
_{1}+ R_{2} - By Ohm’s Law $$I=\frac{V}{{R}_{1}+{R}_{2}}$$

**Example 1**

For the circuit in the diagram above,

- find the reading of the ammeter.
- find the current flows through the resistor.

**Answer**:

a.

Potential difference across the 2Ω resistor, V = 12V

Resistance, R =2Ω

$$\begin{array}{l}V=IR\\ (12)=I(2)\\ I=6\Omega \end{array}$$

b.

The current flows through the resistor

= the reading of the ammeter

= 6Ω

**Example 2**

For the circuit above,

- find the reading of the ammeter.
- find the current flows through each of the resistors.

**Answer**:

a.

Potential difference across the 2 resistors, V = 12V

The equivalent resistance of the 2 resistors, R =6Ω

$$\begin{array}{l}V=IR\\ (12)=I(6)\\ I=2\Omega \end{array}$$

b.

The current flows through the resistors

= the reading of the ammeter

= 2Ω