fusion_title size=”3″ content_align=”left” style_type=”default” sep_color=”” margin_top=”” margin_bottom=”” class=”” id=””]ZIMSEC O Level Combined Science Notes: Resistors in parallel and in series [/fusion_title]

- Resistance in a series can be changed by placing more or less resistors in a circuit
- The total resistance of resistors depends in the way in which they are arranged in the circuit
- Resistors can be put in series or in parallel

**Resistors in series**

- In a series circuit the current only has a single path to follow
- When they are placed in series the total resistance is equal to the sum of the individual resistances
- The formula to find resistance is thus:
- R_{total}=R_{1}+R_{2}+R_{3}+…R_{x}
- For example if there are two resistors in series each with a resistance of 3 ohms
- The total resistance would be:
- 3+3
- 6 Ohms

**Resistors in parallel**

- In a parallel circuit there is more than one path for current to follow
- The most circuit will flow through the path with the least resistance
- If resistors are connected in parallel each one will take some of the current
- The total resistance is lowered because there is alternative routes for the current to follow
- The total resistance of two resistors in parallel can be found using the formula:
- R_{total}=\dfrac{1}{R_{1}}+\frac{1}{R_{2}}+\frac{1}{R_{3}}….\frac{1}{R_{x}}
- For example if two resistors with a resistance of 2 ohms are placed in parallel
- The total resistance will be
- R_{total}=\dfrac{1}{2}+\dfrac{1}{2}
- R_{total}=\dfrac{1}{4} \Omega

To access more topics go to the Combined Science Notes page.