Network Calculations

Voltages & Currents in Resistor Networks

"Find the Missing Values" Quiz

We can use Ohms law and a few basic facts such the Potential Divider rule to usefully work out voltages, currents and resistances in resistor networks; an essential skill in understanding how circuits work and, when fault finding, understanding why they don´t work! Build your skills by working out some unknown values in the circuits below. but before you try this quiz it may be a good idea to look at some basic facts about voltages and currents in resistor networks and some Ohms Law basics.

Ready to Go?

a) 183mA

b) 5.46mA

c) 12mA

d) 2.4mA

2 What is the value of the component current I₁ in circuit 2?

a) 1.25mA

b) 800mA

c) 1.25A

d) 1.26µA

3 Calculate the value of I₂ in Circuit 2

a) 148mA

b) 148µA

c) 6.7mA

d) 39µA

4 Calculate the total resistance R_TOT of Circuit 3

a) 1.36KΩ

b) 278Ω

c) 1.15KΩ

d) 319Ω

5 What is the value of I₁ in Circuit 3?

a) 500mA

b) 8.7mA

c) 21.3mA

d) 47mA

6 Calculate the value of I₂ in Circuit 3

a) 6.8mA

b) 21µA

c) 21mA

d) 14.7mA

7 What is the supply current I_S in Circuit 3?

a) 36mA

b) 8.7mA

c) 47mA

d) 6.8mA

8 Calculate the potential difference V_R2 across R₂ in Circuit 4

a) 3V

b) 2.5V

c) 3.3V

d) 4.5V

9 In Circuit 4, what is the value of the supply current I_S?

a) 1.5mA

b) 1mA

c) 751µA

d) 500µA

10 In Circuit 4, what is the value of R₂?

a) 7.2KΩ

b) 5KΩ

c) 3.3KΩ

d) 33KΩ