Author Topic: IGCSE PHYSICS  (Read 23613 times)

Offline Ghost Of Highbury

  • O_o_O lala!
  • SF Farseer
  • *******
  • Posts: 4096
  • Reputation: 41428
  • Gender: Male
  • Namaskaram!
Re: IGCSE PHYSICS
« Reply #60 on: November 07, 2009, 03:03:11 pm »
@ cooldude chill man...i've seen urs..nd i got it....i said m just looking for alternate ways...!!!stay calm man...take a deep breath in.........and out......cool??!!

@aadi u till didnt get my point man..i know till here...now how did u get 70 fro 49?? is my question.....

dude, thats the easier part.

its simple ratio proportion

70mm - 100
49mm - 100/70 * 49 = 70

got it?
divine intervention!

Offline @d!_†oX!©

  • SF Master
  • ******
  • Posts: 1268
  • Reputation: 2105
  • Gender: Male
Re: IGCSE PHYSICS
« Reply #61 on: November 07, 2009, 03:06:25 pm »
ook guys!!!ya i got it now...will be back when i forget it again!!
Thanks cooldude, nid, aadi, nd shrey(for trying just without even seeing the question)
AAL IZZ WELL!!! ;)

Offline Ghost Of Highbury

  • O_o_O lala!
  • SF Farseer
  • *******
  • Posts: 4096
  • Reputation: 41428
  • Gender: Male
  • Namaskaram!
Re: IGCSE PHYSICS
« Reply #62 on: November 07, 2009, 03:07:29 pm »
ook guys!!!ya i got it now...will be back when i forget it again!!
Thanks cooldude, nid, aadi, nd shrey(for trying just without even seeing the question)

ur welcome

and chill man!..wat if shrey cudnt get it? its k..happens sometimes yaar!. credit nahi dena hai to mat de yaar! :)
divine intervention!

Offline @d!_†oX!©

  • SF Master
  • ******
  • Posts: 1268
  • Reputation: 2105
  • Gender: Male
Re: IGCSE PHYSICS
« Reply #63 on: November 07, 2009, 03:08:19 pm »
arrey yaar mai to uski taang khech raha hun dts it!!! :P
no personal grudges dude!! ;D :D
AAL IZZ WELL!!! ;)

nid404

  • Guest
Re: IGCSE PHYSICS
« Reply #64 on: November 07, 2009, 03:08:50 pm »
ur welcome :)

Offline Ghost Of Highbury

  • O_o_O lala!
  • SF Farseer
  • *******
  • Posts: 4096
  • Reputation: 41428
  • Gender: Male
  • Namaskaram!
Re: IGCSE PHYSICS
« Reply #65 on: November 07, 2009, 03:09:14 pm »
lol..its k.. :P

wasnt this a MCQ question?
divine intervention!

Offline cooldude

  • SF Citizen
  • ***
  • Posts: 172
  • Reputation: 3600
Re: IGCSE PHYSICS
« Reply #66 on: November 07, 2009, 03:11:17 pm »
lol..its k.. :P

wasnt this a MCQ question?

nope, its from the igcse study guide

Offline @d!_†oX!©

  • SF Master
  • ******
  • Posts: 1268
  • Reputation: 2105
  • Gender: Male
Re: IGCSE PHYSICS
« Reply #67 on: November 07, 2009, 03:11:36 pm »
i saw it in a book....bt anyways i have seen this in p3 as well
AAL IZZ WELL!!! ;)

Offline @d!_†oX!©

  • SF Master
  • ******
  • Posts: 1268
  • Reputation: 2105
  • Gender: Male
Re: IGCSE PHYSICS
« Reply #68 on: November 07, 2009, 03:27:04 pm »
i think this thread should be renamed to "adi' questions" .....i think i will fill this whole thread with just my question
okk..so here i go again..
The definition of sound energy is "longitudinal pressure waves that travel through a compressible material"
now my question is that sounds travel through solids...but solids are incompressible...
another addition....sounds waves are a series of compressions and rarefactions....in air, they compress the air molecules...but how do they do that i solid???

AAL IZZ WELL!!! ;)

nid404

  • Guest
Re: IGCSE PHYSICS
« Reply #69 on: November 07, 2009, 04:13:20 pm »
http://www.surendranath.org/Applets/Waves/Lwave01/Lwave01Applet.html


longitudinal waves is not in much detail in the ig syllabus....yeh link mein jaa ke chck the motion of particles....ull understand better

Offline Ghost Of Highbury

  • O_o_O lala!
  • SF Farseer
  • *******
  • Posts: 4096
  • Reputation: 41428
  • Gender: Male
  • Namaskaram!
Re: IGCSE PHYSICS
« Reply #70 on: November 07, 2009, 04:16:47 pm »
The distances between molecules in solids are very small, i.e., solids are more dense - as compared to liquids and gases. Because they are so close, than can collide very quickly, i.e. it takes less time for a molecule of the solid to 'bump' into its neighborough and thus transferring the energy.
divine intervention!

nid404

  • Guest
Re: IGCSE PHYSICS
« Reply #71 on: November 07, 2009, 04:18:17 pm »
Yes in fact in terms of energy......if u actually go to see how energy is transferred u will know how the oscillation n stuff is formed.......anyway abhi ke liye only this much needed

Offline @d!_†oX!©

  • SF Master
  • ******
  • Posts: 1268
  • Reputation: 2105
  • Gender: Male
Re: IGCSE PHYSICS
« Reply #72 on: November 07, 2009, 04:24:13 pm »
okk....but this sounds like a compromise sorts....i mean it shud be in the syllabus dude...
AAL IZZ WELL!!! ;)

Offline moon

  • SF Citizen
  • ***
  • Posts: 222
  • Reputation: 770
Re: IGCSE PHYSICS
« Reply #73 on: November 07, 2009, 05:05:29 pm »
plz, can u help in jun.08 Q4(c), and Jun.07 Q10 (b) need explanation for these questions. thanks.

Offline cooldude

  • SF Citizen
  • ***
  • Posts: 172
  • Reputation: 3600
Re: IGCSE PHYSICS
« Reply #74 on: November 07, 2009, 05:27:20 pm »
plz, can u help in jun.08 Q4(c), and Jun.07 Q10 (b) need explanation for these questions. thanks.


okay so first june 07 q10 b--

see if we want to change the temperature at which the lamp switches on, we have to change the value of resistance R1. if we increase the value of the resistance then more voltage will flow through the transistor and if we decrease the voltage then less voltage will flow through the transistor. therefore if we assume that the amount of heat falling on the thermistor is constant then when we increase or decrease the value of R1 so will the value of the voltage passing through the tranistor will change. so if we want to make the lamp switch on at a different temperature we change the value of R1 because if the heat is falling on the thermistor and thus its resistance decreasing then if the base voltage is enough to switch on the transistor it will light however decreasing the value of the resistor R1 will cause the voltage flowing through the transistor to be too less to switch it on (this is if we want to make the temperature at which the lamp lights more; just explain the opposite thing if u want the temperature at which the transistor lights lower than it is and also u dnt need to expalin all this, ive done this to help u understand it and if u want a shortened version ill be happy to help). therefore in short the temperature at which the lamp lights can be changed by changing the value of R1. (the lamp lights when the base voltage becomes enough for the lamp to switch on)

hope it helps

p.s. i think ive explained a bit too much though


okay now the second q--

see if the temperature increases so will the kinetic energy of the particles. therefore they will exert more pressure in the tube and therefore if the pressure increases the switch will switch on. this is because when we pressed the rubber cover the same thing was achieved but when there is a higher temperature it comes to the same thing

Note--when the transistor switches on it will in turn switch on the lamp
« Last Edit: November 07, 2009, 05:33:50 pm by cooldude »