Physics, Chemistry and Biology: Post your doubts here!

[semsemhosam]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s04_qp_1.pdf
q 24 of physics paper 1 2004
mark scheme says answer is c....i don't get that at all!!

c is correct because the first line will not pass straight , it should be refracted , and passes through F , while the second one passes through the centre of the lens so it will pass straight , the third one will be refracted too and passes through F , so it should be C , remember only the line that passes through the centre of the lens will pass straight , hope that helps & best of luck

 

[semsemhosam]

hi PLLLLLZZZZZZZZZ URGENT!!!!!!! NEED UR HELP GUYS
PLZZZZZZ with explanation

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w11_qp_33.pdf

Q2)c) Q7)d)i)Q8)a)ii) c)

PLLLLLLLZZZZZZZZZZZZZZZZZZZ HELPPPPPP

one more question
if we have 2 stones: 1 heavy and the other is light and air resistance is present
WHICH ONE WILL FALL FIRST IF DROPPED TOGETHER???

1 --> HEAVY: because more mass so more gravitational pull so more weight

2 --> LIGHT: because less air resistance is acting on it while the heavy stone more air resistance is pushing it upward

WHICH ONE OF THE 2 AND IS MY EXPLANATION TO THAT ONE CORRECT??????????

THANKS U V.V.V.V.V.V.V.V.V.V.V.V.V.V.V.V.V.VERY MUCH

for the "one more question"
the heavy one will fall first because it will take more time for the air resistance to balance its weight , while the light one , the air resistance will balance its weight more quickly , ill answer the other questions too Insha'Allah , just wait for a moment pls , hope that helps & best of luck

 

[za Shadow]

for Q1 c) you would do dist/time=800/320=2.5 s then use v=at where a is g because the stone is falling under gravity. so 2.5x10=25 m/s
Q7 i guess there should be no change in ammeter reading. it is only measuring the urrent across the 2 ohm resistor.
Q8a)(ii)it would move down on the left (-)ive side and up on the right(+)ive side (anticlockwise) because the motion of the coil is always normal to direction of flow of curent and at right angles to the magnetic field according to Fleming's left hand rule.

c) where there is current produced, e.m.f. is induced in the coil. direction of induced e.m.f. is such that it will cause effects to oppose the current. electric current is a fiorm of energy and when the coil is moved against the electromagnetic force work has to be done in overcoming this force. so the current or energy is graually reduced as it is needed in overcoming this electromagnetic force.

THANK U VERYYYYYYYYYYYYYYYYYYYYYYYYY MUCH U R THE BEST

 

[za Shadow]

for the "one more question"
the heavy one will fall first because it will take more time for the air resistance to balance its weight , while the light one , the air resistance will balance its weight more quickly , ill answer the other questions too Insha'Allah , just wait for a moment pls , hope that helps & best of luck

THANK U VERYYYYYYYYYYYYYYYYYYYYYYYYY MUCH U R THE BEST

 

[AAnsarii]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s04_qp_1.pdf
q 24 of physics paper 1 2004
mark scheme says answer is c....i don't get that at all!!

Look at d middle ray; a ray through the optical centre C is undeviated, it won't change direction n will pass straight through.
All d best

 

[semsemhosam]

THANK U VERYYYYYYYYYYYYYYYYYYYYYYYYY MUCH U R THE BEST

ur wlcm

 

[semsemhosam]

hi PLLLLLZZZZZZZZZ URGENT!!!!!!! NEED UR HELP GUYS
PLZZZZZZ with explanation

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w11_qp_33.pdf

Q2)c) Q7)d)i)Q8)a)ii) c)

PLLLLLLLZZZZZZZZZZZZZZZZZZZ HELPPPPPP

one more question
if we have 2 stones: 1 heavy and the other is light and air resistance is present
WHICH ONE WILL FALL FIRST IF DROPPED TOGETHER???

1 --> HEAVY: because more mass so more gravitational pull so more weight

2 --> LIGHT: because less air resistance is acting on it while the heavy stone more air resistance is pushing it upward

WHICH ONE OF THE 2 AND IS MY EXPLANATION TO THAT ONE CORRECT??????????

THANKS U V.V.V.V.V.V.V.V.V.V.V.V.V.V.V.V.V.VERY MUCH

Q2) c. first we have to find the time , so 800/320 = 2.5 s
u know the formula v=at , a is the acceleration , so we'll use the acc. of free fall
so v = 10 x 2.5
=25 m/s
Q7 ) d . (i) the thick piece of wire will have resistance too , u know the formula r=l/d
so the answer is it will stay the same .
Q8) a. (ii) use the flemings left hand rule , it will be anticlockwise direction
hope that helps & best of luck

 

[za Shadow]

Q2) c. first we have to find the time , so 800/320 = 2.5 s
u know the formula v=at , a is the acceleration , so we'll use the acc. of free fall
so v = 10 x 2.5
=25 m/s
Q7 ) d . (i) the thick piece of wire will have resistance too , u know the formula r=l/d
so the answer is it will stay the same .
Q8) a. (ii) use the flemings left hand rule , it will be anticlockwise direction
hope that helps & best of luck

it sure did thanks again
but for q7 the thick wire should have less resistance so why it will stay the same

 

[semsemhosam]

it sure did thanks again
but for q7 the thick wire should have less resistance so why it will stay the same

it is SORTED OUT , so it should be of the same resistance

 

[kboss]

Look at d middle ray; a ray through the optical centre C is undeviated, it won't change direction n will pass straight through.
All d best

thanks but how will the third ray refract so..."radically"!!!

 

[AAnsarii]

thanks but how will the third ray refract so..."radically"!!!

i don't get NE logic 2 xplain dat..., maybe just look at d ray at d centre, in no other 1 is it passing straight.
Ne way, All d best 4 Monday's xam, i think its then right?

 

[kainat husain]

Physics help ..
http://www.mediafire.com/?k4k67e1mkdhezr4
Question 11 .. How is the answer C .. the volume is getting decreased so the pressure is supposed to decrease as well isnt it ??

ASALLAM O ALIKUM!
the answer is C because when volume decreases pressure increases they are inversely proportional.. and B is not the answer because The pressure of a fixed mass of gas in a cylinder is measured. The volume of the gas in the
cylinder is then slowly decreased.
So that's y its C
i hope you get it
best of lucky

 

[kboss]

i don't get NE logic 2 xplain dat..., maybe just look at d ray at d centre, in no other 1 is it passing straight.
Ne way, All d best 4 Monday's xam, i think its then right?

yup...the exam's on monday along with p-4 maths OMG!!!!

 

[semsemhosam]

yup...the exam's on monday along with p-4 maths OMG!!!!

yea , that's the worst thing they ever thought about , Insha'allah we'll be able to think about physics after maths without confusions

 

[kboss]

yea , that's the worst thing they ever thought about , Insha'allah we'll be able to think about physics after maths without confusions

after??

 

[kainat husain]

Fats are are esters as far as I remember. They are made up of carboxylic acids and alcohols.
Im not too good in chemistry but the answer should be ester.

thanks

 

[kainat husain]

Please can some one help me understanding saponification

 

[kboss]

Please can some one help me understanding saponification

as far as i remember saponification isn't actually in the syllabus and even if it is...to date it hasn't been asked (much...it may have been bt im unaware of it )

 

[semsemhosam]

after??

yes ! i have ath p4 at 11 am and physics p1 at 3 pm

 

[kboss]

really?! that's weird....i have physics at 10 AM and maths at 1300...:/