Biology; Chemistry; Physics: Post your doubts here!

[Xialay Khan]

question numver 24 : D (its a fact )
31: B ( in series the combined resistance of three resistors = 6

Ω ​

So, the resistor of each resistor. their combined resistance will be 2/3 Ω​

32 : A ( according to the fleming's LHR, the beam of electrons deflicts into the page.​

35 :A ( when the switch is opened, the current stops flowing in the upper circuit and the iron in the lower circuit drops and comes in contact with the metal . The lower circuit is then completed and the bell rings .​

​

38 : C (undecayed atoms ​

nuclide X​

16000 after 1 day 8000​

8000 after 2 days 4000 and so on...​

Undecayed atoms​

nuclide Y​

2000 after 2 day 100​

1000 after 4 day 500 ​

500 after 6 days 250​

​

Hence , the number of undecayed atoms nuclide X will be equal to the numbers of atoms of nuclide Y after 6 days​

​

 

[khizer shahab]

http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Physics (5054)/5054_w10_qp_12.pdf can anyone solve Q24. Q31 q32, 35 and 38

24 d
31 b
35 a

24 by diverging lens image formed slightly similar to magnifying glass i.e formed at the side of object usually on left, so virtual,upright and diminished bcuz fromed in between lens and object
31 use formula 1/rt= 1/ri + 1/rii +1/riii
35 as the switch s is opened solenoid would loose its field thus iron would fall ,completing the circuit of bell !!

confused with 38th

 

[khizer shahab]

question numver 24 : D (its a fact )
31: B ( in series the combined resistance of three resistors = 6

Ω ​

So, the resistor of each resistor. their combined resistance will be 2/3 Ω​

32 : A ( according to the fleming's LHR, the beam of electrons deflicts into the page.​

35 :A ( when the switch is opened, the current stops flowing in the upper circuit and the iron in the lower circuit drops and comes in contact with the metal . The lower circuit is then completed and the bell rings .​

​

38 : C (undecayed atoms ​

nuclide X​

16000 after 1 day 8000​

8000 after 2 days 4000 and so on...​

Undecayed atoms​

nuclide Y​

2000 after 2 day 100​

1000 after 4 day 500 ​

500 after 6 days 250​

​

Hence , the number of undecayed atoms nuclide X will be equal to the numbers of atoms of nuclide Y after 6 days​

​

please explain in detail the last part

 

[Xialay Khan]

please explain in detail the last part

well they are asking for the number of days when these two atoms of nuclide will be the same ...so... sort it out by dividing the number of days by the number of radioactive atoms at time ...per day day per timr ..like as ive shown already

(undecayed atoms​

nuclide X​

16000 after 1 day 8000​

8000 after 2 days 4000​

4000 after 3 day 2000​

2000 after 4 day 1000​

1000 after 5 day 500​

500 after 6 day 250​

Undecayed atoms​

nuclide Y​

2000 after 2 day 100​

1000 after 4 day 500​

500 after 6 days 250​

this is why we call it the half life.....hope u got it this time ?​

 

[ayeshaK]

http://www.xtremepapers.com/papers/...nal O Level/Biology (5090)/5090_w10_qp_62.pdf
Can any ody help me with this magnification question!! I just need to now that while measuring the lenght of specimen do we have to measure the whole seed or theembryo inside ?

 

[Spidey21]

http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Biology (5090)/5090_w10_qp_62.pdf
Can any ody help me with this magnification question!! I just need to now that while measuring the lenght of specimen do we have to measure the whole seed or theembryo inside ?

i think you will have to make just the seed because when its germinating the seed coat is removed

and the marking scheme states
2 (a) (i) Drawing:
1. at least 6 cm, clear and clean ;
2. accurate shape of embryo ;
Labels: radicle ;
plumule
stem or root origin correctly identified ;

 

[Lilpumpkin]

anyone can explain briefly for balancing the equations?

 

[SalmanPakRocks]

anyone can explain briefly for balancing the equations?

It's easy.
Let's suppose we have this neutrilization reaction
NaOH + H2SO4 ----- Na2SO4 + H2O
now count the number of each of the element in start of reaction
we have
Na = 1
O = 5
H = 3
S = 1

Now count the number of element in end of reaction.
Na = 2
S = 1
O = 5
H = 2

now simply first of all balance sodium and hydrogen by following:
2NaOH + H2SO4 ------ Na2SO4 + 2H2O
now we have
Na = 2, O = 6, H = 4, S = 1
Na = 2, S = 1 , H =4 O =6
thus equation is balanced.

 

[Lilpumpkin]

thank you that helped
will be out for more xx

 

[SalmanPakRocks]

thank you that helped
will be out for more xx

Sure, no problem. In return pray for me.

 

[Spidey21]

Sure, no problem. In return pray for me.

why are we not allowed to discuss the paper for atleast 24hrs after the paper?? :S

 

[SalmanPakRocks]

why are we not allowed to discuss the paper for atleast 24hrs after the paper?? :S

That's the rules. You can't.
Back on topic, please.

 

[Lilpumpkin]

Sure, no problem. In return pray for me.

okay x

 

[Spidey21]

Can someone explain this?
As seen on: http://www.xtremepapers.com/revision/gcse/chemistry/metals.php

haha
nope no one can explain this...

 

[Spidey21]

question numver 24 : D (its a fact )
31: B ( in series the combined resistance of three resistors = 6

Ω ​

So, the resistor of each resistor. their combined resistance will be 2/3 Ω​

32 : A ( according to the fleming's LHR, the beam of electrons deflicts into the page.​

35 :A ( when the switch is opened, the current stops flowing in the upper circuit and the iron in the lower circuit drops and comes in contact with the metal . The lower circuit is then completed and the bell rings .​

​

38 : C (undecayed atoms ​

nuclide X​

16000 after 1 day 8000​

8000 after 2 days 4000 and so on...​

Undecayed atoms​

nuclide Y​

2000 after 2 day 100​

1000 after 4 day 500 ​

500 after 6 days 250​

​

Hence , the number of undecayed atoms nuclide X will be equal to the numbers of atoms of nuclide Y after 6 days​

​

correctly done

you get the WATER COOLER!

 

[Spidey21]

(a) Every minute, water with kinetic energy 14 000 J emerges from the pipe. The water turns a
turbine that is connected to the generator.
Half of the kinetic energy of the water is given to the generator.
(i) Calculate the power input to the generator.

sorry to disturb for a basic question but i was not getting the right answer
i was getting 116 w something while the ms states its 120 w...please help..

 

[Spidey21]

That's the rules. You can't.
Back on topic, please.

(a) Every minute, water with kinetic energy 14 000 J emerges from the pipe. The water turns a
turbine that is connected to the generator.
Half of the kinetic energy of the water is given to the generator.
(i) Calculate the power input to the generator.
help bud!!

 

[SalmanPakRocks]

(a) Every minute, water with kinetic energy 14 000 J emerges from the pipe. The water turns a
turbine that is connected to the generator.
Half of the kinetic energy of the water is given to the generator.
(i) Calculate the power input to the generator.
help bud!!

I guess the question is incomplete, can u provide me with the year?
This would be done by this formula
E=PT

 

[Spidey21]

http://www.xtremepapers.com/papers/...nal O Level/Physics (5054)/5054_s11_qp_21.pdf
here you go..

 

[Spidey21]

I guess the question is incomplete, can u provide me with the year?
This would be done by this formula
E=PT

question 3!!