Physics Half Yearly Questions (2 Viewers)

[rheyn]

Re: I screwed up my half yearlies

"there is maximum force when the the force is perpendicular to the magnetic field"
sounds very odd.

Yeah I was aware of that when I was writing it, but this force that I'm referring to is the force which provides a torque but not the force from Torque=Fd where, here, force is defined as the force perpendicular to d.

"When the force is maximum (i.e. when the the force is perpendicular to the magnetic field), the coil plane must be parallel to the magnetic field."
Not really in a motor.

Lol You're right, but we're talking about a galvanometer

 

[Pwnage101]

Re: I screwed up my half yearlies

lol easy guys, no need to turn this thread into personal attacks

 

[gutzeit]

Re: I screwed up my half yearlies

"ROFL"ing at this guy who had the audacity to claim he knew something about Physics (sorry ), and yet proceeded to spout that:



Mate you have no clue about how galvanometers work! If your "plasma physicist" gave you this explanation, please tell him to stop inhaling the plasma and do something useful with it instead.

[/SIZE]

This is coming from somebody who didn't even know about the application of the motor effect to the moving coil galvanometer (and of course someone who wasn't smart enough to pick up on some really obvious sarcasm), something that the syllabus requires.

Oh and, Helper does seem like somebody who does know their stuff, you on the other hand, demonstrate the integral characteristics of a curr.

Ok dudes, go here: HowStuffWorks "Galvanometer"
And you will find this:

"The galvanometer makes use of the fact that an electric current flowing through a wire sets up a magnetic field around the wire. In the galvanometer, the wire is wound into a coil. When current flows through the coil, one end of the coil becomes a north magnetic pole, the other a south magnetic pole. When a permanent magnet is placed near the coil, the two fields—the one from the coil and the one from the magnet—interact. The like poles will repulse each other and the unlike poles will attract. The amount of attraction and repulsion increases as the strength of the current increases."

I realise this is half a year later, but yes. There you go.

Perhaps none of you can agree, because you're all incorrect.

Just because the textbooks say something doesn't mean it's correct.

You can continue placing trust in physics teachers, but I prefer the ideology of cutting the middle man and going straight to the top.

 

[helper]

Re: I screwed up my half yearlies

Ok dudes, go here: HowStuffWorks "Galvanometer"
And you will find this:

"The galvanometer makes use of the fact that an electric current flowing through a wire sets up a magnetic field around the wire. In the galvanometer, the wire is wound into a coil. When current flows through the coil, one end of the coil becomes a north magnetic pole, the other a south magnetic pole. When a permanent magnet is placed near the coil, the two fields—the one from the coil and the one from the magnet—interact. The like poles will repulse each other and the unlike poles will attract. The amount of attraction and repulsion increases as the strength of the current increases."

I realise this is half a year later, but yes. There you go.

Perhaps none of you can agree, because you're all incorrect.

Just because the textbooks say something doesn't mean it's correct.

You can continue placing trust in physics teachers, but I prefer the ideology of cutting the middle man and going straight to the top.

Pity that source is using a stage 5 answer and doesn't explain it to a HSC level. It fails to talk about the motor effect, torque, balancing of the torque suppplied by the spring and motor effect or how a magnetic field is caused around the coil, or at least why its north or south. It totally fails to explain why the galvanometer can turn either direction.

 

[cutemouse]

Re: I screwed up my half yearlies

Ok dudes, go here: HowStuffWorks "Galvanometer"
And you will find this:

"The galvanometer makes use of the fact that an electric current flowing through a wire sets up a magnetic field around the wire. In the galvanometer, the wire is wound into a coil. When current flows through the coil, one end of the coil becomes a north magnetic pole, the other a south magnetic pole. When a permanent magnet is placed near the coil, the two fields—the one from the coil and the one from the magnet—interact. The like poles will repulse each other and the unlike poles will attract. The amount of attraction and repulsion increases as the strength of the current increases."

I realise this is half a year later, but yes. There you go.

Perhaps none of you can agree, because you're all incorrect.

Just because the textbooks say something doesn't mean it's correct.

You can continue placing trust in physics teachers, but I prefer the ideology of cutting the middle man and going straight to the top.

What about the motor effect? Faraday's law?