Which unit is resistance measured in?
An 8 Ω resistor and a 12 Ω resistor sit one after the other in a series loop. Together they behave like one single resistor. How big is that one resistor?
Together the pair opposes the current exactly as one 20 Ω resistor would. The resistance of that single stand-in resistor is called the circuit's total resistance.
And 8 + 12 = 20: the resistances add.
Swap the 12 Ω resistor for a 30 Ω resistor, and the pair behaves like 8 + 30 = 38 Ω.
Wire in a third resistor of 15 Ω, and the three behave like 8 + 30 + 15 = 53 Ω.
In the equation, R_total is the total resistance of the series combination, and R₁, R₂, and so on are the individual resistances. Every value is in ohms.
The total is always bigger than any one resistance in the chain.
Two different resistors sit in series. Compared with the larger one alone, the total resistance is…
Which operation gives the total resistance of resistors in series?
This rule is for series only. Components that sit on separate branches are not in series, and their resistances do not simply add.
A 9 Ω bulb filament and a 16 Ω resistor sit in series. What total resistance do they give?
Write down the values in the question:
R₁ = 9 Ω; R₂ = 16 Ω; R_total = ?
Write down the equation:
R_total = R₁ + R₂
Substitute in the values, and calculate:
R_total = 9 + 16 = 25
The total resistance is 25 Ω.
Leo says two resistors in series oppose the current more than either resistor does alone. Is Leo correct?
A series circuit contains several resistors. Which rule gives the circuit's total resistance?
A 14 Ω buzzer coil and a 26 Ω resistor sit in series. What is their total resistance?
Another resistor is wired into a series circuit. What happens to the circuit's total resistance?