mod 6 phys question (1 Viewer)

[kractus]

how would you do this?

 

[unofficiallyred12]

is it C?

 

[qldbulls]

I'm not 100%, but treating it like this pearson textbook question,

I think the answer would be C. As the part of the wire is dropping in height, the earth field strengthens at a max rate, and so by Lenz's law the wire counteracts by emitting circle fields which go in the opposite direction of the earth's (thinking about the top portions of the concentric circle field lines) , inducing a current from P to Q through the moving portion.

 

[unofficiallyred12]

you can also do f = qvb for the sea of delocalised electrons in the copper wire lmao

 

[qldbulls]

you can also do f = qvb for the sea of delocalised electrons in the copper wire lmao

What on earth is this person talking about

 

[wizzkids]

@kractus We are looking for the points where the rate of change of the area of the loop is maximum. That will give the maximum ΔΦ/Δt
That would be at points A or C.
We are looking for an induced current that flows clock-wise in the loop from P to Q.
The static part of the loop of wire P-G-Q is orthogonal to the Earth's magnetic field. It plays no part in the induced current, (apart from closing the circuit).
The moving part of the loop P-Q causes the area enclosed by the loop to increase and decrease in a harmonic motion.
Now the Earth's magnetic field is directed into the page, we know that from the diagram showing points X and Y on the map of the Earth.
Now we have to decide in which direction the induced current flows, in order to pick between A or C.
I suggest we make use of Lenz's Law to solve this one.
Lenz's Law states that the induced current will attempt to oppose the change that caused it.
When the wire is going up (A), the number of lines of magnetic flux into the page and enclosed by the loop is increasing, therefore the induced current will produce lines of magnetic flux out of the page.
When the wire is going down (C) the number of lines of magnetic flux into the page and enclosed by the loop is decreasing, therefore the induced current will produce lines of magnetic flux into the page.

Now do you think you can finish this off?

 

[esybeast]

What on earth is this person talking about

i think he means treat points (A, B, C, D) as single electron, use hand rule. flip for conventional current to find A, B, C or D. Since direction of magnetic field known, direction of current is given. by applying the opposite hand of hand rule you use for the lorentz force. direction of force = movement of the wire.

 

[nsw..wollongong]

why is everyones pfp wednesday adams