# Lesson : Combination Circuit Exercises

Before you dive into the multiples exercises, you can find a cheat sheet for Ohm’s law, Power law, series and parallel circuit at this page.  You can find the cheat sheet for Voltage Divider, Kirchhoff’s laws and combination circuit at this page. This will be useful to solve the exercises.

Exercise 1:

In this exercise, we want to find every missing values. Let’s assume $R_1$ = 10kΩ (10000), $R_2$ = 10kΩ (10000), $R_3$ = 3kΩ (3000), $R_4$ = 1.5kΩ (1500) and $R_5$ = 2kΩ (2000). We want to find $V_1$, $V_2$ and $V_3.$ We also want to find $I_1$, $I_2$, $I_3$, $I_4$ and $I_5.$ $I_1$ is the current flowing into $R_1$, $I_2$ is the current flowing into $R_2$ and so on.

(Note : k means you multiply the number by a thousand)

For the current, make sure to choose the appropriate unit. (uA or microamps is multiply by $10^{-6}$, mA or milliamps is multiply by $10^{-3}$). uA is one millionth of an ampere and mA is a thousandth of an ampere. $V_{1}$: Volt $V_{2}$: Volt $V_{3}$: Volt $I_{1}$: $I_{2}$: $I_{3}$: $I_{4}$: $I_{5}$:

Exercise 2:

In this exercise, we want to find every missing values. Let’s assume $R_1$ = 1kΩ (1000), $R_2$ = 1kΩ (1000), $R_3$ = 2kΩ (2000), $R_4$ = 3kΩ (3000) and $R_5$ = 4kΩ (4000). We want to find $V_1$ and $V_2.$ We also want to find $I_1$, $I_2$, $I_3$, $I_4$ and $I_5.$ $I_1$ is the current flowing into $R_1$, $I_2$ is the current flowing into $R_2$ and so on. You will also need to calculate the total current flowing into the circuit $I_{tot}.$

(Note : k means you multiply the number by a thousand)

For the current, make sure to choose the appropriate unit. (uA or microamps is multiply by $10^{-6}$, mA or milliamps is multiply by $10^{-3}$). uA is one millionth of an ampere and mA is a thousandth of an ampere. $V_{1}$: Volt $V_{2}$: Volt $I_{1}$: $I_{2}$: $I_{3}$: $I_{4}$: $I_{5}$: $I_{tot}$:

You now have completed the Chapter 2 of Learn Electronics. In the next chapter, we will move on to a different topics. We are not done yet with resistors but we will dive into the digital world of electronics before coming back to more complex resistors circuits. Like this chapter, you will have examples and exercises at the end of chapter 3.