Chalter 23 Magentic Fields Clarification On What Happens With Wire/ Vs Coil In Mag Field, E= Blv And DROPPING A MAGNET INTO A COIL

Question 1

So what happens in full when you drop the magnet into a coil
2) what happens to the SPEED and motion indische the coil
Is g constant etc?

What is speed at the end compared to start snd why?

Answer 1

When entering, we said it experiences a force opposite to it, and this won’t be equal to the weight , so it will accelrwteless but not terminal velocity

At middle point, the emf induced is =0, and thus no force acts except for g, at this point it accelerates at g instaneouslyn

At the end , again there is an attractive force, so accerlwtion is less than g.

2) at the end, as it was accelerating the whole way through , you’d expect it to be at a auciker speed. And in general for the whole last half of the coil, it exits at a quicker speed

Question 2

So what happens in full when you drop the magnet into a coil
3) now we know the speeds explain why the shape of the graoh is a HIGHER peak when leaving compared to entering?

• and WHAT happens to the time between 0 and last peak compared to entering and first peak

Answer 2

This is because the same amount of FLUX is changed in a LESS TIME, resulting in More emf

As a result the peak for the graoh is higher for when it exits compared to when it entered

2) the time is less, as it exits at Higher speed!

Question 3

So what happens in full when you drop the magnet into a coil

3) what would happen to emf and time if dropped from higher then?

Answer 3

As dropped higher, it enters at higher velocity due to more time allowed for object to acclerate under g

Enteign at higher v means same flux changed in less time, so more emf induced

Overall more emf induced, second peak still higher than first, but the TOTAL TIME IS LESS

Question 4

Finally describe graoh from start to finish

Answer 4

Starts from emf 0 at t 0, when it approaches the top of the coil it increases emf until maximum emf is reached as soon as it enters coil, then when it keeps going into coil, emf decreases as rate of change if emf devreases until there is no rate at 0, so once at middle emf is 0

Then while it exits the rate increases again, but faster than before as now higher velocity, so in LESS TIME , it escapes, but also leaves at a HIGHER EMF , due to same change of flux happening in less time due to it accelrwtijg all the way thriguh

Question 5

For the coil and use of e =. Luv, to cicurlar coil and why thid soden stork and plane explanation, look at other pack?