# HNC science

hi guys can anyone give me any advice on where to begin for the question below i keep overcomplicating it and really dont know where to start?

a) Consider the DC circuit below.
Use the principle of Superposition to determine the following circuit parameters.
i. The current through R1
ii. The voltage across R1
iii. The current through R2
iv. The voltage across R2
v. The power dissipated in R3
(edited 6 months ago)
to do superposition you break the problem down to a series of circuits containing one power source
you solve all those circuits one at a time and then add up the answers at the end to get the answer for the actual circuit with all the power sources in it.

it's OK if one stage shows a current going through a resistor in the opposite direction to the current you calculate another stage... you sum them up at the end and the answer comes out alright - e.g. if you had two power sources and your first calculation had a current of 10 Amps left to right and your second had 3 Amps going right to left the answer would be 7 Amps left to right

This is a decent explanation IMO https://www.allaboutcircuits.com/textbook/direct-current/chpt-10/superposition-theorem/

Batteries are voltage sources so when you need to replace a battery you replace it with wires - you might not have met current sources yet