Physics MCQs thread.

[Arshiful]

Summer 04 #9 pls some one explain this ques to me in details......

confirm it first, if it's right. i will post my workings. is it D ?

Yes it is D pls explain .........

 

[hassam]

 

[hassam]

COME ON ZISHI...THEY R TUFF RYT..?

 

[xHazeMx]

D & C

 

[xHazeMx]

Summer 04 #9 pls some one explain this ques to me in details......

confirm it first, if it's right. i will post my workings. is it D ?

Yes it is D pls explain .........

vertically,
U= 0
S= 1.25
a= 9.81
t= ??
find t using S= ut + 1/2 at^2
now u have the value of t which is 0.50 s
horizontally, the velocity is constant, for constant velocity we have the equation v=s/t
so v= 10 (horizontal distance) / 0.50 = 20

 

[asdfg12345]

http://www.xtremepapers.me/CIE/Internat ... 7_qp_1.pdf

Q37. Please help
why the resistance is the same, cos i thought when the cross sectional area is smaller, the resistance of the wire should be higher.

 

[Arshiful]

thnx @xhazemx

 

[xHazeMx]

http://www.xtremepapers.me/CIE/International%20A%20And%20AS%20Level/9702%20-%20Physics/9702_s07_qp_1.pdf

Q37. Please help
why the resistance is the same, cos i thought when the cross sectional area is smaller, the resistance of the wire should be higher.

the bars have no resistance. the rod is made into thin wires of the SAME LENGTH and the current is allowed to pass through the WHOLE wires which has equal cross sectional area as that of the rod. Hence, there is no effect on the resistance so resistance P and Q are the same

 

[Hateexams93]

 

[xHazeMx]

is it A ? if it's correct i'll explain

 

[Flash667]

Yes, my logic says it's A. We should take kinetic energy conservation for this as it is an elastic collision. Set up an equation & ignore the masses, we get A.

 

[Hateexams93]

yes

 

[xHazeMx]

yes

alright there is an equation which u have to memorise ( Ux + Vx = Uy + Vy ) .. apply this formula taking care of directions and u will find it

 

[Arshiful]

http://www.xtremepapers.me/CIE/International%20A%20And%20AS%20Level/9702%20-%20Physics/9702_s07_qp_1.pdf

Q37. Please help
why the resistance is the same, cos i thought when the cross sectional area is smaller, the resistance of the wire should be higher.

read the q again before reading it:
same material (i.e) copper so resistivity (rho"P") same
length in both case same (x)

in P
takin cross sec area= 56 cm^2
so R=Px/56

in Q lets divided the area equally into given seven wires

cross sec of each wire is 8 cm^2
resistance of each wire = Px/8

in Q wires are connected in parallally, we know 1/R=1/R1 + 1/R2+ 1/R3+ 1/R4+ 1/R5+ 1/R6+ 1/R7, where R1=R2=R3=R4=R5=R6=R7

so total resistance of Q

1/R= [1/(Px/8)]*7
1/R= 56/Px

R = Px/56

resistance of P= Resistance of Q

C is the answer (remember both are made of copper so equal resistivity "P")

 

[Hateexams93]

yes

alright there is an equation which u have to memorise ( Ux + Vx = Uy + Vy ) .. apply this formula taking care of directions and u will find it

thats the thing , i know that formula but when i'm applying it , i'm not getting the wright answer , can u just do it ?

 

[icanhelp]

q 2 guys
pls
answers not c

 

[yubakkk]

can any one post the force extension graph of rubber glass copper steel etc??
by drawing and screening it??

 

[Zishi]

Others are easy, hassam. I saw these questions now. This one would be easy if my answer is correct. LOL

For densities one, I get their ratio as 2.25.

 

[Karimgenena]

its A

 

[abdullah181994]