Any electricians/electrical engineers?

[Migwire]

I'm currently doing an HNC in mechanical engineering. Part of the engineering science module is electrical.

I have to analyse a circuit and use Superposition Theorem. I calculated the values given a couple of times to find current "I". What I'm unsure of though is can your value for "I" be a negative number? Or do I just swap the subtraction around to give a positive answer? Surely you can't have a negative current?

 

[A4_MaJiK]

I'd have to get my notes out for this one, but I'm pretty sure you're right about not being able to have a negative current.

 

[Migwire]

I think I've just done the sum the wrong way round to be honest. In my worked examples to find I you subtract I3 from I1 in all of my examples I1 is greater than I3. In my case I1 is lower than I3, which so 0.66A-1.12A = -0.46A switching it around though, 1.12A-0.66A = 0.46A, but that means I'm subtracting I1 from I3 then.