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 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 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.