physics mcqs HELP !

[ammarelahi]

Please explain me N06 Q31, J07 Q36, N07 Q23, N09 QP12 Q11,Q13,Q16 and Q26
I will be very grateful !!!

 

[mz23]

hey do you know how to do n06 question 21??? please tell me asap! i will get to your questions in a while

 

[ammarelahi]

well I tried it this way = take height of oil as X and height of water as 2000-X
then form an equation using density x gravity x height for both the liquids and equate it to total pressure
(830 x 9.8 x X) + 100 x 9.8 x(2000-X)= 17.5Mpa
solve for X
I am getting answer as 1261m and the correct answer is D
hope this helps

 

[mz23]

ok thanx! i did the same but what i dont understand is that why are we not taking atmospheric pressure into account?

 

[ammarelahi]

neither did i

 

[mz23]

lol ok thanks!

 

[ashhadazam]

Nov 06 Q31..

I=Q/t = (Q x 1/t)
F=1/t
substitute F in place of 1/t
so it become I=QF

total charge=4Q therefore current = 4Qf

 

[ashhadazam]

J07 Q.36

Total current =3/6 =0.5

V across resistor = 0.5 x 4 = 2
Power = V^2/R ... 2^2/4 =1
THe ans is C

 

[ammarelahi]

@ashhadazam thnx man .....can u explain me the others??????

 

[hamizahmed]

N 07 Q23
since you do not know frequency, first find it out

speed=freq x wavelength

8=f x 50
f=0.16Hz

since the ques is asking abt da max kinetic energy, amplitude will be 2, take our da speeed at dat instance using the formula given

v=2 x pi x af
v=2 x pi x 2 x 0.16

v=1.98

K.E= 1/2mv^2
K.E= .5(2x10^-3)(1.98)^2
K.E= 3.92x10^-3
approx 4
option B is the ans

 

[ammarelahi]

explain J03 Q10, Q32 and Q40 PLEASE PLEASE PLEASE !

 

[ashhadazam]

Q.32)
U will take the voltage 7.5V and not 9V because the drop shows the voltage drop by internal resistance..
SO the I becomes 7.5/15 = 0.5A

Q.40)U need to add and minus the charges of quarks in such a way that u get +1 which is the charge of proton. this is only given by option D as 2 upquarks would give u +4/3 and 1 down quark would giv u -1/3 . add them u get 3/3 which is equal to +1.

 

[ashhadazam]

Q.10) total a is constant for both masses which is given by F=4ma where F is the total force and ma=F/4.. now for block Y the mass is 3m and F for it is given by 3ma but ma=F/4 there for F on block y =3F/4

 

[ammarelahi]

@ashhadazam thanks lot. which country r u from and how many papers r u giving ???

 

[leena]

can any one tell me how 2 solve Q20 in oct/nov 2001 plz

 

[princesszahra]

its on A2 phy
try solving leena

 

[PlanetMaster]

I guess that paper isn't in our download section.
Can you provide the question?

 

[princesszahra]

its a big one with drawing
its work done by the gas
and workdone =pressurex change in volume
so answer for workdone is 0.375
so the answer is B

 

[ashhadazam]

I m from Pakistan.. 4 papers AS U ?? Pray for me Phy p1 And best of luck to all of you too

 

[ammarelahi]

me 2 and giving 4 papers as well !!!
can somebody tell me what is terminal voltage and whats its formula ???