Cambridge Physics Problems: Electrostatics

[johnconnor]

Before I go about trying to futilly solve the question, is this thing beyond a CIE A-Lv physics student's reach or not? Any comments on the difficulty of the question, and perhaps the reading material which you would recommend before I attempt the question?

Thank you.

 

[Infinitum]

Hi johnconnor

I don't exactly know what level CIE A-Lv is, but I am a grade 12 student, and the problem looks quite simple to me. What about it do you not understand? The first part, for example, simply relates to the Superimposition principle

 

[johnconnor]

Hi johnconnor

I don't exactly know what level CIE A-Lv is, but I am a grade 12 student, and the problem looks quite simple to me. What about it do you not understand? The first part, for example, simply relates to the Superimposition principle

Well yeah I can kind of explain the first part too - albeit in a un-professional way. But for the remaining parts, I was like WTH coz I've never dealt with electrostatic questions of this length.

The guide says:

This is a piece of physics that used to be a standard part of any electromagnetism course because magnetism was taught from the starting point of a short bar magnet with a N-pole at one end and S-pole at the other (...) If the distance from P to Q is written r(1 - a/r), the binomial expansion may be used where necessary, and this will simplify the algebra when adding the effect of -Q. Note that, because electric fields are vectors whereas potentials are scalars, each of the these quantities must be added accordingly (the point of the first part of the question).

One thing about CIE Physics is that it deals with rather narrow topics and emphasises with greater analysis on the questions, which is why I have touched very little on electrostatics.

Is grade 12 year 12 in UK? Which education system do you follow actually?

 

[Infinitum]

This is a piece of physics that used to be a standard part of any electromagnetism course because magnetism was taught from the starting point of a short bar magnet with a N-pole at one end and S-pole at the other (...) If the distance from P to Q is written r(1 - a/r), the binomial expansion may be used where necessary, and this will simplify the algebra when adding the effect of -Q. Note that, because electric fields are vectors whereas potentials are scalars, each of the these quantities must be added accordingly (the point of the first part of the question).

That's a bit confusing to explain this specific problem, and I don't see any real need to look at it the bar magnet way...

I would look at it as a dipole. What is the electric field due to a dipole along its axis?

 

[johnconnor]

I would look at it as a dipole. What is the electric field due to a dipole along its axis?

Actually I'm still quite stuck at parts (a) and (b). I haven't gone through the HCl part.

Is grade 12 year 12 in UK? Which education system do you follow actually?

What about this, Infinitum? =)

 

[Infinitum]

Actually I'm still quite stuck at parts (a) and (b). I haven't gone through the HCl part.

Well, that part also relates a dipole...A dipole has two charges of equal and opposite magnitude placed at a certain distance.

What about this, Infinitum? =)

I think yes, grade 12 is year 12 in UK.