Author Topic: ALL PHYSICS DOUBTS - POST HERE !!  (Read 230896 times)

Offline Ivo

  • SF Geek
  • ****
  • Posts: 515
  • Reputation: 2767
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1785 on: May 26, 2010, 10:52:55 am »
What abt this one ::) I really don't get it?   ???

Four metal rods are placed, in turn, inside a coil of copper wire.
Which rod would be the most suitable to use for the core of a coil in a circuit breaker?

number of paper clips picked up when there is a current in the coil:     number of paper clips still attracted when the current is switched off:
A                                 1                                                                                            0
B                                 20                                                                                           2
C                                 35                                                                                           0
D                                 35                                                                                           30





C, right.  Cos you want a electromagnet which magnetisises and demagnetises easily.  Electromagnets lose magentism when current is siwtiched off, that's why it's zero when off.
Always willing to help!  8)
"In helping others, we shall help ourselves, for whatever good we give out completes the circle and comes back to us."

6394

  • Guest
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1786 on: May 26, 2010, 10:53:37 am »
@ kimo jesus n dana wen r u ppl gettin ovr wid phy ppr 1
because m done  ??!11??!!

Offline dodi23

  • Before you meet your prince you have to kiss a lot of toads.
  • SF Master
  • ******
  • Posts: 1418
  • Reputation: 2963
  • Gender: Female
  • MAN made beer, GOD made weed. Who do you trust?
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1787 on: May 26, 2010, 10:54:38 am »
soo how wz it??
_________________________________
l__l__l__l__l__ll__ll__ll__ll__ll__l__l\_?_\___
l__dodi23's_ limousine___________________l=
""(@)@)''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''(@)

Offline Ghost Of Highbury

  • O_o_O lala!
  • SF Farseer
  • *******
  • Posts: 4096
  • Reputation: 41428
  • Gender: Male
  • Namaskaram!
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1788 on: May 26, 2010, 10:54:59 am »
aadi  for u

a women tune her radio to a station broadcasting on 200m

what does 200m tell her about the radio wave?

freq

wave leng

sped

ampl

if m is meter, shud be wavelength. although, the wavelength of medium wave radio is 100 m...anyway...
divine intervention!

Offline Dana

  • SF Immigrant
  • **
  • Posts: 87
  • Reputation: 122
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1789 on: May 26, 2010, 10:56:09 am »
C, right.  Cos you want a electromagnet which magnetisises and demagnetises easily.  Electromagnets lose magentism when current is siwtiched off, that's why it's zero when off.
That's what I was thinking.. I'll check and tell you. Thanks alot!

Offline Dana

  • SF Immigrant
  • **
  • Posts: 87
  • Reputation: 122
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1790 on: May 26, 2010, 10:56:43 am »
@ kimo jesus n dana wen r u ppl gettin ovr wid phy ppr 1
because m done  ??!11??!!
My exam's in about 2 hours
how was it???

Offline Weaam

  • Mad Alice
  • SF Geek
  • ****
  • Posts: 411
  • Reputation: 2264
  • Gender: Female
  • What if I spoke alien, fluently? O.o
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1791 on: May 26, 2010, 10:56:58 am »
Can anyone tell me how to magnetise steel?
And how to demagnetise it?
Thank You! ;D
- The man who smiles when things go wrong has thought of someone to blame it on. - Robert Bloch.
-I saw weird stuff in that place last night. Weird, strange, sick, twisted, eerie, godless, evil stuff... and I went in. - Homer
+ Rep me if i have been of any assistance to you ;D

Offline WARRIOR

  • SF Master
  • ******
  • Posts: 1473
  • Reputation: 51196
  • Egyptian And so damn proud . I love you jesus!
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1792 on: May 26, 2010, 10:57:14 am »
What abt this one ::) I really don't get it?   ???

Four metal rods are placed, in turn, inside a coil of copper wire.
Which rod would be the most suitable to use for the core of a coil in a circuit breaker?

number of paper clips picked up when there is a current in the coil:     number of paper clips still attracted when the current is switched off:
A                                 1                                                                                            0
B                                 20                                                                                           2
C                                 35                                                                                           0
D                                 35                                                                                           30




its C

why? caz elctro magnets should be magnetic whn the current is switched off !

and which attraacts more  A or C ..whn current is on? C

im doin the exam in 2 hours an haa half
NO secrets to SUCCESS , it is the result of 1.HARD WORK 2.GOOD PREPARATION 3.LEARNING FROM FAILURE
But it ain't how hard you hit; it's about how hard you can get hit, and keep moving forward-Balboa

Offline Ivo

  • SF Geek
  • ****
  • Posts: 515
  • Reputation: 2767
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1793 on: May 26, 2010, 10:57:31 am »
Can anyone tell me how to magnetise steel?
And how to demagnetise it?
Thank You! ;D

https://studentforums.biz/index.php/topic,7946.msg210346.html#msg210346
Always willing to help!  8)
"In helping others, we shall help ourselves, for whatever good we give out completes the circle and comes back to us."

Offline the_grim_reaper

  • SF Citizen
  • ***
  • Posts: 160
  • Reputation: 180
  • Gender: Male
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1794 on: May 26, 2010, 10:57:45 am »
@ kimo jesus n dana wen r u ppl gettin ovr wid phy ppr 1
because m done  ??!11??!!

Don't worry Lad. It's still 12:55 PM in KSA and my paper is at 3 PM. So there's still A LOT of time left for everyone to get rid of paper 1 :D :D.

(Don't worry I don't want to know if it was hard or easy or whatever. If I fail, I'll fail on my own. It I pass, I'll pass on my own. Way of the Samurai :D :D :D)....

Offline Ivo

  • SF Geek
  • ****
  • Posts: 515
  • Reputation: 2767
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1795 on: May 26, 2010, 10:58:17 am »
Can anyone please clear doubt about magnetism.  So ferrous materials can be magnetised (e.g. iron and steel).  All ferrous materials can be magnetically induced (so both sides of a magnetic object attracts).  

However, a magent has poles.  To make magnet, you place in d.c. current.

I'm not sure, but am i right in saying that in magnetic induction, the thing being induced is not a magnet, because it does not have magnetic field lines?

By the way, iron is magnetically soft, so loses magnetism easily right?


Please can someone answer my qu. thanks a lot!
Always willing to help!  8)
"In helping others, we shall help ourselves, for whatever good we give out completes the circle and comes back to us."

Offline Dana

  • SF Immigrant
  • **
  • Posts: 87
  • Reputation: 122
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1796 on: May 26, 2010, 10:58:38 am »
its C

why? caz elctro magnets should be magnetic whn the current is switched off !

and which attraacts more  A or C ..whn current is on? C

im doin the exam in 2 hours an haa half
Thanks :)

Offline Dana

  • SF Immigrant
  • **
  • Posts: 87
  • Reputation: 122
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1797 on: May 26, 2010, 10:59:51 am »
Don't worry Lad. It's still 12:55 PM in KSA and my paper is at 3 PM. So there's still A LOT of time left for everyone to get rid of paper 1 :D :D.

(Don't worry I don't want to know if it was hard or easy or whatever. If I fail, I'll fail on my own. It I pass, I'll pass on my own. Way of the Samurai :D :D :D)....
Noooo I wanna know if it was easy or difficult! So i can brace myself uno? :P
I'm doing it in Saudi too! Which city are you in?

holtadit

  • Guest
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1798 on: May 26, 2010, 11:00:27 am »
How ???

See below.

Offline Vin

  • SF V.I.P
  • ********
  • Posts: 7914
  • Reputation: 52609
  • Gender: Male
    • Theory of Life - A new skew.
Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1799 on: May 26, 2010, 11:01:57 am »
How ???

See below.

you can place it in a known Temperature .. to calibrate