Biology; Chemistry; Physics: Post your doubts here!

[Starlight97]

anyone of you could plz help me with MCQ q9 /p1/nov 08 of phys

 

[angelrockxxx98]

which format for electronic configuration should be followed ????????? in olevel examinations in chemistry???
EITHER 1s2,2p2.....................
or K2M8N2

 

[Queens]

which format for electronic configuration should be followed ????????? in olevel examinations in chemistry???
EITHER 1s2,2p2.....................
or K2M8N2

the second one

 

[Shahmeer Khan]

22 and 12

Are you sure????

 

[mohdumar]

yeah i got my provisional statement of entry

 

[mohdumar]

Nopes it supposed to be concentrated if u still are confused check the answer for a CIE question on Electrolysis where they say the products on anode when aqueous NaCl is electrolysed,its bound to be Cl2 and not O2 !

exactly my case!!!

 

[mohdumar]

anyone of you could plz help me with MCQ q9 /p1/nov 08 of phys

we know that F=ke

for 1st diagram first part

F=ke
force = 1N
k is unknown
extension of spring unknown, let it be e
so
1=ke

for 1st diagram second part

F=ke
force=2N
k is unknown
extension is now e+1 (previous extension plus 1cm)
so
2=k(e+1)

solve simulatenously
1=ke
2=k(e+1)
we get e=1 and k=1

now, for 2nd diagram 1st part
the spring combination is parallel,
so for overall spring constant of whole combination "newK" we have to add spring constant of each individual spring. we know that k=1 from above so
newK = k + k = 1+1 =2

(if the spring combination had been in series, we would have added reciprocal of each individual spring constant
1/newK = 1/k + 1/k )

lets find extension of this diagram
F=ke
e=F/k
force=1N
k=2
so e=1/2 = 0.5


for 2nd diagram second part
find extension
e=F/k
force= 2N
k=2 as found above
so extension=2/2 =1

now to find 'x' for mcq answer
subtract extension of load 1N from extension of load 2N
1-0.5 = 0.5

answer = A) 0.5

 

[papajohn]

20) The oxide of an element X increases the rate of decomposition of hydrogen peroxide. At the end
of the reaction the oxide of X is unchanged.
Which details are those of X?
proton number---- mass number
A 18 -------------40
B 20------------- 40
C 25--------------- 55
D 82 --------------207

 

[scouserlfc]

20) The oxide of an element X increases the rate of decomposition of hydrogen peroxide. At the end
of the reaction the oxide of X is unchanged.
Which details are those of X?
proton number---- mass number
A 18 -------------40
B 20------------- 40
C 25--------------- 55
D 82 --------------207

Basically it means that A,B,C or D one of them is a catalyst which actually increases the RATE of decomposition of H2O2 and is UNCHANGED at end ! these are all catalyst property so just get the periodic table and see which one is a transition metal !
Answer is C which is Manganese !

 

[papajohn]

Basically it means that A,B,C or D one of them is a catalyst which actually increases the RATE of decomposition of H2O2 and is UNCHANGED at end ! these are all catalyst property so just get the periodic table and see which one is a transition metal !
Answer is C which is Manganese !

Understood. Thankx

 

[Mariyam zia]

hey in have A Reall Pro in Physics ATP plzz help me im really confuse
i have not started them yet Tipsssssssssss

 

[Mariyam zia]

help in Physicss ATP
Plzzzzzzzzzzzzzzzzzzzzzzzzzzzzz Tipssssssssssss

 

[Queens]

help in Physicss ATP
Plzzzzzzzzzzzzzzzzzzzzzzzzzzzzz Tipssssssssssss

It's basically practice . Just solve the past papers , you don't need to study a book or anything the Physics ATP is general knowledge really. Look at the past papers to see what kind of questions are asked.
The questions that ask you to name sources of error in an experiment or the consecuquent remedies are the ones that are time consuming. So just look at the marking scheme for a bunch of errors. The experiments are similar so , just memorize a few errors and write them whemever such a question comes.
Apart from that physics atp is not that difficult. Keep solving papers, you'll get the hang of it.
You will miss these simple ATP papers when you start Alevels

 

[Mariyam zia]

hmmmmmmmmmmmmmmmmmmm okay i'll try doing that Thnkxxx

 

[Mariyam zia]

hey if i start doing them now will i able to finish them before may? and ya would it be better starting them from 2003-2012

 

[ArOoj Jaleel]

I need specimen paper 2013 fOr Physics and Add Maths... sOmeone can help??

 

[mohdumar]

I need specimen paper 2013 fOr Physics and Add Maths... sOmeone can help??

http://www.xtremepapers.com/community/threads/additional-maths-4037-specimen-paper-2013.23100/

 

[Mariyam zia]

i neeed it tooo

 

[Queens]

hey if i start doing them now will i able to finish them before may? and ya would it be better starting them from 2003-2012

One past paper a day , keeps the tension away.
start in whatever sequence you like . the point is to solve past papers .

 

[Mariyam zia]

thnkxx