ALL PHYSICS DOUBTS - POST HERE !!

[Ghost Of Highbury]

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/imgmag/magcur.gif
[/quote

ok try this, make ur fingers as shown in the diagram...the way the fingers are wrapped around show how the magnetic lines will be...
check the diagram..check the red arrows which indicate the magnetic field an and direction..

only the red arrow near C matches the compass arrow..

[WARRIOR]

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/imgmag/magcur.gif
[/quote

ok try this, make ur fingers as shown in the diagram...the way the fingers are wrapped around show how the magnetic lines will be...
check the diagram..check the red arrows which indicate the magnetic field an and direction..

only the red arrow near C matches the compass arrow..

aadi can u explain to me why the barometers diamter doest affect height? i kno by heart that it doesnt..but for what reason exactly..( dont say the area doesnt affcet height  or say with with a good reason )

[Malak]

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/imgmag/magcur.gif

ok try this, make ur fingers as shown in the diagram...the way the fingers are wrapped around show how the magnetic lines will be...
check the diagram..check the red arrows which indicate the magnetic field an and direction..

only the red arrow near C matches the compass arrow..

Get it now..Thx

[Ghost Of Highbury]

aadi can u explain to me why the barometers diamter doest affect height? i kno by heart that it doesnt..but for what reason exactly..( dont say the area doesnt affcet height  or say with with a good reason )

ok here

The weight mercury in the barometer = AHdg,

where 'A' = area of cross-section

H' is the height of the mercury column

d is the density

g is the acceleration due to gravity = 9.8 m/s^2

But the pressure p is the weight per unit area.

So if you divide AHdg by 'A' you get p=Hdg i.e p = height*density*acc. due to gravity

You can now notice that the pressure is independent of the value of the cross-sectional area ((diamter/2)^2 * pi)

[WARRIOR]

ok here

The weight mercury in the barometer = AHdg,

where 'A' = area of cross-section

H' is the height of the mercury column

d is the density

g is the acceleration due to gravity = 9.8 m/s^2

But the pressure p is the weight per unit area.

So if you divide AHdg by 'A' you get p=Hdg i.e p = height*density*acc. due to gravity

You can now notice that the pressure is independent of the value of the cross-sectional area ((diamter/2)^2 * pi)

i seeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee !

thanks man uv been really helpful !

[Ghost Of Highbury]

Ur welcome.

[Malak]

How come the answer is D?

[Ghost Of Highbury]

If they were on earth, he wud hear the loud sound. but in space, he cant hear it, so no sound at all. Sound needs a medium to travel, in space, theres vacuum, no air particles, thus no sound.

[WARRIOR]

SOUND = VIBRATION OOF MOLECULES


NO AIR IN THE MOOOOOOOOOON  ( NO MOLECULES )

NO VIBRATION

[Malak]

M so dumb...I thought they are asking wat would he hear on earth...Pff!!

Thx both

[Malak]

Q13 & 21

http://www.freeexampapers.us/IGCSE/Physics/CIE/2007%20Nov/0625_w07_qp_1.pdf

Thx

[Vin]

Q13 & 21

http://www.freeexampapers.us/IGCSE/Physics/CIE/2007%20Nov/0625_w07_qp_1.pdf

Thx

ok Q

13) D, always wen the pressure increases mercury level rises .. and the space P is always a vacuum .. so it is not affected by pressure

21)B, the ques says "still water" so water in the space AB will take the space BC wen there are no waves hence the surface is B

[The Golden Girl =D]

ok Q

13) D, always wen the pressure increases mercury level rises .. and the space P is always a vacuum .. so it is not affected by pressure

21)B, the ques says "still water" so water in the space AB will take the space BC wen there are no waves hence the surface is B

Vin i am so sleepy so i'm going to log off.......FYI u've got chem pp1 tomorrow , so go sleep young man !!

[Baladya]

Hey, if u have any doubts with Thermal Properties, i made this for ya
https://studentforums.biz/index.php/topic,8099.0.html

U can ask me warever u want

[Vin]

Vin i am so sleepy so i'm going to log off.......FYI u've got chem pp1 tomorrow , so go sleep young man !!

yea i know.. im sleepy too .. best of luck ... if u happen to read this ..