Physics MCQs thread.

[yubakkk]

as ballis thrown up so g is acts downwd so a is negative
so ans is d

why can't it be C?

when it hit then accleration change for short time
as it must hit on half time of return back so only d

 

[Mobeen]

http://www.xtremepapers.me/CIE/index.php?dir=International%20A%20And%20AS%20Level/9702%20-%20Physics/&file=9702_s10_qp_11.pdf
qs 17,29 with explaination and 36

some one help...plz

 

[yubakkk]

q. 18
http://www.xtremepapers.me/CIE/index.ph ... _qp_11.pdf

 

[Xthegreat]

can u xplain me of q.18 of this year??
i m doing 2 give ur ans.....
plz if u know 18 then...

u mean O/N10 12 Q18?
well, its quite simple cause the molecules will always have a range of energies
evaporation occurs at all times, meaning molecules will leave the surface of water.
and besides gas which have negligible attractive force, liquid and solid have significant attractive forces.

 

[rabib2013]

answer is B
can anybody explain?

 

[arlery]

C

 

[yubakkk]

can u xplain me of q.18 of this year??
i m doing 2 give ur ans.....
plz if u know 18 then...

u mean O/N10 12 Q18?
well, its quite simple cause the molecules will always have a range of energies
evaporation occurs at all times, meaning molecules will leave the surface of water.
and besides gas which have negligible attractive force, liquid and solid have significant attractive forces.

i m taking about may 2010 ppr 11 q.18

 

[cocospaniel]

Q31, nov 2008, variant 1. I got C, but the answer is B, can someone explain why?

 

[arlery]

why is the answer B? =S

 

[yubakkk]

u hav forget to equate voltage
asthey are in parallel so pd same
so irp=irq
then u will get

 

[arlery]

Q31, nov 2008, variant 1. I got C, but the answer is B, can someone explain why?

Hope this helps:

 

[rabib2013]

C

umm, was that the answer to my question?
cause the actual answer is B.

 

[Xthegreat]

can u xplain me of q.18 of this year??
i m doing 2 give ur ans.....
plz if u know 18 then...

u mean O/N10 12 Q18?
well, its quite simple cause the molecules will always have a range of energies
evaporation occurs at all times, meaning molecules will leave the surface of water.
and besides gas which have negligible attractive force, liquid and solid have significant attractive forces.

i m taking about may 2010 ppr 11 q.18

ooh, the question says it CONTRACTS
so the distance obviously decrease
density=m/v, mass is the same but volume decreases, so density increases.

 

[yubakkk]

plz any one fast...??

 

[ninjas4life]

why is the answer to this c and not b? dosnt electric field strength decrease when plates are further?

 

[arlery]

Use the equation of motion d = ut + 0.5at^2

equation 1 : 40 = 12u + 72a

equation 2 : 80 = 18u + 162a

[I added the distances, so that initial speed of both equations will be same]

now solve these simultaneously, and you will get 0.37 m/s^2 as the answer.

 

[cocospaniel]

why is the answer B? =S

Use the formula, lambda = W(dist between fringe)*a(distance between slits)/D(dist between slits and fringe). We keep the units to mm.
lambda= (1 * a)/D, 2nd equation, lambda= (3*d)/D+2*10^3

Lambda is equal to 600 for both. So equate both equation.
Do some algbera until you get 2Da-2000a. Now simply it to 'a(2D-2000)'=0. So D = 1000

Now they asked for (a), so now that we have D
we can use lambda=a/D

600*10^-6 (mm) * 1000 (mm) = d = 0.6 mm. Hope this helps

 

[rabib2013]

answer is B
can anybody explain?

anyone???

 

[arlery]

why is the answer to this c and not b? dosn't electric field strength decrease when plates are further?

At first I was confused too, but then I realized, they didn't ask us if the distance between the plates is increased. They asked us how the electric field will vary along with distance d along the line XY hence the electric field will be constant at any distance between the plates.

 

[yubakkk]

electri field is constant so..