Author Topic: ALL PHYSICS DOUBTS - POST HERE !!  (Read 225234 times)

Offline Vin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1890 on: May 26, 2010, 01:47:23 pm »
Ok, for this first u have to determine the North and South poles of the solenoid. That u have to determine by Lenz's law. Now North always has anticlockwise current right? So u simply draw the arrow for the direction of current. The Ammeter needle will deflect in the direction of the current. Simple. :) like in the case of ur diagram, it will move towards the right side, cuz htat's where the current is goin

i get it

but the needle of the meter moves the opposite side too when the magnet is removed .. so can u explain that too ??

Offline jellybeans

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1891 on: May 26, 2010, 01:48:05 pm »
I think ur right.. :P wht does the MS tell?

for the first one, C is marked 'vertically'(?) under/at any peak & R is marked on next to trough ... but i dont get if it cud be "on" the trough. :/
for the spectrum thing, "refraction and dispersion at first face, refraction and dispersion at second face"
You said I must eat so many lemons cause I am so bitter.

holtadit

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1892 on: May 26, 2010, 01:49:17 pm »
Thanks for this! i was just about to request the answer to it :) But one thing's bugging me. Why'd they give us the diagram of the house? Aren't those switches that are drawn in the diagram in the question...I'm gettin confused with that :)

Those are DOORS

Offline Fastal

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1893 on: May 26, 2010, 01:50:33 pm »
i get it

but the needle of the meter moves the opposite side too when the magnet is removed .. so can u explain that too ??

the needle moves the opposite side because the induced current reverses, since now the left side of that coil has become the north pole to attract the south pole being put in.(remember lenz law)

Offline Raywin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1894 on: May 26, 2010, 01:52:08 pm »
for the first one, C is marked 'vertically'(?) under/at any peak & R is marked on next to trough ... but i dont get if it cud be "on" the trough. :/
for the spectrum thing, "refraction and dispersion at first face, refraction and dispersion at second face"

Im clueless.. :S but i think ur right.. :)
;D

holtadit

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1895 on: May 26, 2010, 01:54:39 pm »
I DONT GET LENZ's LAW  !!!!!



Please explain with a diagram how to predict which way the current flows with Lenz Law

 :'( :'( :'(

Offline ambitious94

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1896 on: May 26, 2010, 01:55:14 pm »

Offline jellybeans

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1897 on: May 26, 2010, 01:56:56 pm »
Im clueless.. :S but i think ur right.. :)

hahaha okay. thanks :)
You said I must eat so many lemons cause I am so bitter.

Offline jellybeans

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1898 on: May 26, 2010, 01:57:27 pm »
WHAT HAPPENS TO THE WAVELENGTH AS IT TRAVELS TO A LESS DENSE MEDIUM? D: D:
You said I must eat so many lemons cause I am so bitter.

holtadit

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1899 on: May 26, 2010, 01:57:52 pm »
WHAT HAPPENS TO THE WAVELENGTH AS IT TRAVELS TO A LESS DENSE MEDIUM? D: D:

Increases

Offline jellybeans

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1900 on: May 26, 2010, 01:58:42 pm »
You said I must eat so many lemons cause I am so bitter.

Offline Moonlyte

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1901 on: May 26, 2010, 01:58:50 pm »
erm...how exactly do you attach images?

holtadit

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1902 on: May 26, 2010, 02:00:24 pm »
erm...how exactly do you attach images?

When posting click on additional options ;)

Offline ambitious94

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1903 on: May 26, 2010, 02:00:49 pm »
I DONT GET LENZ's LAW  !!!!!



Please explain with a diagram how to predict which way the current flows with Lenz Law

 :'( :'( :'(
Lenz's law states that:direction of induced current always opposes the motion that produces it.
When we bring a magnet towards a solenoid with the North Pole towards the solenoid's side, the solenoid tries to repel the magnet, by making the end closest to the magnet NORTH too.
Now, when the magnet is drawn away (N side still towards solenoid), the solenoid tries to ATTRACT the magnet by making it's end SOUTH, therefore current reverses.
Summary: When you bring the magnet TOWARDS the solenoid, it tries to repel. When you pull the magnet AWAY from the solenoid it tries to ATTRACT.
How does it do that? By changing it's poles!
AAH...I KNOW SUMTHING...YAY!

Offline Fastal

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1904 on: May 26, 2010, 02:01:32 pm »
OK

I use the Right hand grip rule for the direction of current, except reverse.

Lenz's law-The direction of the induced current is such as to oppose the change causing it so in Diagram the coil will be induced with a North pole at the top to OPPOSE the magnet being put inside. Now use the Right Hand Grip rule and the current will go in the direction indicated.Note:the magnet is moving into the coil in the diagram.

same way when you move the magnet out of the coil it tries to attract it thus inducing the current the OTHER way
« Last Edit: May 26, 2010, 02:03:12 pm by Fastal »