Recent content by JoeN

I thought as much for the distance. Thanks very much for everyone's help

Thanks for the responses by the way, but really need a quick answer to this. Does the distance from the lens to to the light sources affect the focal length? I would have assumed not, but in a preliminary test the lens was increased in distance from the light source and the focal length...

I see. So would this affect the value for u? I was measuring from the filament of the lamp to the middle of the lens, but would it be accurate to measure from the concave lens to the middle of the convex lens in that case? Not entirely sure I follow, sorry. If the focal length is the middle of...

I did use parallel light as the input, but how could that make u infinity?.. And thanks, but I think you missed the question. I know how to use the formula, and know that the output is focal length, but why is this a different value to v? In diagrams the focal length is the middle of the lens...

Homework Statement My physics coursework hypothesis: "As the thickness of the lens increases, the focal length decreases". I tested this using a ray box, a stand to hold lenses and a screen to see where the light is most focused, which is then measured with a metre ruler. The distance 'u'...

I'm not in a position to perform the experiments again, unfortunately, I just have to evaluate the data. 1) Battery dying is likely. They have probably been used many times before I did the experiment. So a dying battery can eventually recover some voltage and decrease in resistance for a...

My preliminary data: length of wire V A1 A2 mean ohms 10 0.28 1.20 1.25 1.23 0.23 20 0.24 1.21 1.22 1.21 0.20 30 0.32 1.10 1.16 1.13 0.28 40 0.30 1.11 1.13 1.12 0.27 50...

I'm doing coursework on a circuit experiment we performed in class. I'm pretty sure the results are wrong or flawed, but we were testing the effect of increasing the length of wire on the resistance. I had a voltmeter about the wire, a cell, an ammeter, and completed the circuit by attaching the...

I see. Thank you very much for your time. Circuits have been troubling me for quite a while.

The overall current is reduced, but the individual current readings through the resistors are equal to each other and the overall current?.. If a current is 2A without any resistors, adding two will decrease the current, to say 1A, and this will be the current through the resistor. Is that...

http://www.youtube.com/watch?v=u-7k8wpl_ZU&list=PLBCCF1129FCAE29DF&index=12&feature=plpp_video There are three resistors in a series circuit. The video states that the current through the resistors is the same, or 'I = I1 = I2 = I3'. EDIT: Ah, I see what you mean... so, the overall current is...

I can't get my head around this: How can the current in a series circuit be unchanged by any amount of resistors? 1) I understand that there is only one path, and thus; 2) I understand that the charge isn't used up. BUT. If current is the charge passing a point per second, and resistors...

Hi guys, sorry as this is probably a silly question. This isn't homework, but it's something I'm confused about in my GCSE course. If a lattice of ions can't conduct electricity when solid, then why can a wire (composed of these lattices (I think?)) conduct electricity? The electrons in a...