AP Physics 2 / Unit 11: Electric Circuits
11.5 Compound Direct Current (DC) Circuits
Notes
- Series: $R_{eq}=R_1+R_2+\dots$, same current.
- Parallel: $\displaystyle \frac{1}{R_{eq}}=\frac{1}{R_1}+\frac{1}{R_2}+\dots$, same voltage.
- Adding a resistor in parallel lowers $R_{eq}$.
Practice
4 Ω and 6 Ω in series. $R_{eq}=$
Add.
6 Ω and 3 Ω in parallel. $R_{eq}=$
$\displaystyle \frac{1}{6}+\frac{1}{3}=\frac{1}{2}$.
Adding another bulb in parallel to a battery makes the total current:
Lower total resistance.
Ready for more? Take the Unit 11 test.