AS Physics P1 MCQs Preparation Thread.

[Silent Hunter]

Let x be the speed of body 'm', and y be the speed of body '2m'.

0 = mx - 2my
mx = 2my
x = 2y

Shouldnt the yellow part be : 0 = -mx + 2my ..... it wont make any difference i guess in the answer but still

 

[Ahmed Ali Akbar]

anyone pls exp these ques 23 25 35 nd40 for 35 why voltmeter reading is zero ammeterreadgis clear need help pls gys

look ..in q 35..both in diagram 1 and diagram 2 resistors are in parallel wth other 2...and if u make an equivalent circuit diagram for diagram 2...it will be same as diagram 1..and voltmeter would at same place as it was in diagram 1....hope it will help to some extent...

 

[leosco1995]

why dont you multiply by two for question 15? ... i mean you have two containers each with mgh/4 , thus that wud leave u with mgh/2 ???

also Q18) why would you include the decrease of a distance on the LHS, like can you explain it?

The pressure in a manometer involves the height difference between the RHS and the LHS, it has always been like that. If you increase one side by, say, 2 cm, the other side would be reduced by 2 cm and the difference in height would be 4 cm. But if you mean to say why do we use the height difference in finding the pressure, I don't know, I was just told that that's how the formula is.

For Q15) Oh.. I thought they were asking about the potential energy lost in X... in that case my explanation is wrong so please disregard it.. I'll try to solve it and then post a proper solution after.

 

[leosco1995]

Shouldnt the yellow part be : 0 = -mx + 2my ..... it wont make any difference i guess in the answer but still

Yeah, you can take - and + as any direction you want, as long as you stick to them all the time.

BTW, please ignore my explanation of Q15, it's wrong I think. I didn't read the Q properly. Once/if I get the right answer I will explain it. Or if you get it, then explain it to me.

 

[Silent Hunter]

Yeah, you can take - and + as any direction you want, as long as you stick to them all the time.

BTW, please ignore my explanation of Q15, it's wrong I think. I didn't read the Q properly. Once/if I get the right answer I will explain it. Or if you get it, then explain it to me.

okay me waiting

 

[xxfarhaxx]

sum hlp needed !!
Q- 2, 31, 34
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s04_qp_1.pdf
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s04_ms.pdf

Q- 13, 16, 27, 32
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s05_qp_1.pdf
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s05_ms_1.pdf

Q- 3, 9 , 11, 15, 20, 28
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w05_qp_1.pdf
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w05_ms_1.pdf

ppl postn dis fr da 2nd tm!!!!!!

 

[iKhaled]

need help in may june 2005

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s05_qp_1.pdf
Q13
Q16
Q21
Q29​

 

[ughani99]

http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_w10_qp_11.pdf

Question 37 can someone explain it

 

[kinglynx]

Yeah, you can take - and + as any direction you want, as long as you stick to them all the time.

BTW, please ignore my explanation of Q15, it's wrong I think. I didn't read the Q properly. Once/if I get the right answer I will explain it. Or if you get it, then explain it to me.

Actually, they asked for the potential energy lost by the WATER, which i guess includes the whole system, i think it doesnt matter what the actual volume of the water is, it just depends on the height and mass due to the equation thus you dont multiply by two.
Btw leosco1995, can you please check out my question here

https://fbcdn-sphotos-a.akamaihd.ne...x720/282891_10150999944406535_846620522_n.jpg

 

[Peter Check]

k u knw ouput / input * 100 = efficency so here it will be 4 * 10^ 6 / input * 100= 80 so u get input = 5 * 10^6 W
so power / voltage = current
5*10^6/ 25000 = 200 A.
i might be wrong if so let me knw but i think dis is how we cn do it.

yeah ur right but I dont get it, how can the locomotive operate at the maximum input power of 5*10^6 when the efficiency is clearly not 100%?

 

[Ahmed Ali Akbar]

I know this is a lot of questions but please do help fellows. Thanks........

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s07_qp_1.pdf
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s07_er.pdf
Q8 Q10 Why isnt answer D? average force= change in P/change in t = (-p2-p1)/(t2-t1) =(simplifying) (p1+p2)/(t2-t1) rite??
Q13, 20 Q 23 Why not A? Q40 How do we find its answer. Examiner report mentions q/m ratio has to be lowest. what is q/m ratio??

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s08_qp_1.pdf
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s08_er.pdf
Q6 Why wont there be a change in speed if the object is accelerating?
Q13, 14 am always get these type of questions wrong....any particular method to solve them?
Q22 Why not B? And what is the difference btw limit of proportionality and elastic limit?
Q 24??? How do we solve it? i got 8E and thats not even one of the options. if diameter is halved then doesnt the area decrease by a factor of four and length is doubled so by simplifying we get 8E. But answer is E.......

Q ..8..A is answer...coz distance is directly proportional to v2-u2..i.e...final velocity square minus initial velocity square...therefore we cant simply use 10 meter to find time...as i said..v2-u2 will be different and hence answer will be wrong...in q 10..u are dead right..we cant do anything about ths question,he has asked to to find expression for force,force is simply rate of change of momentum..i.e mv- mu/t..p2-p1/t2-t1 is answer//or p1-p2/t2-t1..
torque equals force multiply perpendicular distance between forces...to take perpendicular distance we will have to to take forces perpendicular..so take vertical component of force and multiply it with 0.60m....cos30 multiply 8 multiply 0.60m..or another simple method .whenever force is at angle to horizontal/vertical..multiply force with sin of angle...as in ths case sin 60 multiply force multiply 0.60..u'll get the same answer...i cant help in q 20...though its not in syllabus...acceleration is max at max displacement...u would have get this after eliminating others..

 

[A.ELWY 7]

ppl postn dis fr da 2nd tm!!!!!!

any thing for J 2004 go to the AS pysics p1 mcq YEARLY ONLY thread and ull find all 2004 answered..for j 2005
Q 13: moment = F x perpendicular distance...clockwise = anti clock wise...so ( 10 x 2) +(20 x 3)= (5 x 2) ...answer is 30 so A
Q 16: SRY CANT HELP
Q27: speed of electromagnetic waves is 3 x 10^8 ms-1...distance between 2 adjacent minima or maxima is 0.5 lambda so...0.5 lambda=0.015m...lambda = 0.03...f= v/lambda= 3x 10^8 / 0.03 = 1 x 10^10 so C
Q32:wait a little more time and ill answer

 

[Ahmed Ali Akbar]

Tilt the images next time.

For the 1st one, tension always acts on the outer edge of a bar and compression always acts on the inner edge. So there will be tension at X and Z and compression at Y. Another way of solving is imagining what will happen to the forces when the weight is pulled.

For the 2nd one, the strings are in simple harmonic motion. Think of a pendulum. The speed will be maximum at the centre (as in point Q) and zero furthest away from the centre (as in point S and P). And the acceleration will be maximum furthest away from the centre. So D is right.

Look up some notes on basic SHM.

why acceleration is max at max displacement...at max displacement kinetic energy is zero,velocity is zero..then how we can hve max acceleration...

 

[A.ELWY 7]

need help in may june 2005​

​

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s05_qp_1.pdf​

Q13​

Q16​

Q21​

Q29​

i answered 13 and dont know 16..
Q21: its easy to understand them as the answer is D because glass is brittle and so it will break at a certain point..so it is graph Z as the graph suddenly stops...steel is ductile means can be drawn to wires and ductile materials always have a grah like the graph Y...as a small increase in F causes a large increase in x and the only left one is graph X for the rubber because it is polymeric
Q29:i solved it this way...i got an imaginary number for d and theta and used the equation d sin theta= n lambda...when i got lambda aproximately 600 when i divided by two..i did the same thing but divided by three and got 400 and so it is B..i dont know how will u do it

 

[A.ELWY 7]

any thing for J 2004 go to the AS pysics p1 mcq YEARLY ONLY thread and ull find all 2004 answered..for j 2005
Q 13: moment = F x perpendicular distance...clockwise = anti clock wise...so ( 10 x 2) +(20 x 3)= (5 x 2) ...answer is 30 so A
Q 16: SRY CANT HELP
Q27: speed of electromagnetic waves is 3 x 10^8 ms-1...distance between 2 adjacent minima or maxima is 0.5 lambda so...0.5 lambda=0.015m...lambda = 0.03...f= v/lambda= 3x 10^8 / 0.03 = 1 x 10^10 so C
Q32:wait a little more time and ill answer

For Q 32... what i know to get the number of charges or electrons passing per secon is to divide the current by the charge..i did it and it worked...10/( 1.60 x 10^-19)

 

[leosco1995]

why acceleration is max at max displacement...at max displacement kinetic energy is zero,velocity is zero..then how we can hve max acceleration...

It is possible for a body to have acceleration when velocity is zero. e.g. what is the initial acceleration of a ball thrown from the top of a building? It's -9.81 but the velocity is zero and displacement is at its maximum. This is sort of comparable to SHM. Over here the restoring force (gravitational force) is at its maximum and since F = ma, this means that the acceleration is also at a maximum.

 

[leosco1995]

okay me waiting

OK I got it now (I got help from elsewhere):

The P.E depends on the centre of gravity, not the height.

Initially, at column X, the P.E is mgh.
Initially, at column Y, the P.E is 0 because there is no c.o.g. and therefore no height.

After half of the water is filled on both sides,
At column X, the centre of gravity is now halved (so 1/4th of the height 'h') and P.E is mgh/2.
At column Y, the centre of gravity is at 1/4th of the height 'h' also, so the P.E is mgh/4.

So column X went from mgh/2 to mgh/4.
And column Y went from 0 to mgh/4.

Total loss in P.E -> Loss in Column X + gain in Column Y.
= -mgh/2 + mgh/4
= -mgh/4

Tricky question, it seems.

 

[Ahmed Ali Akbar]

please answer the questions above. second time I'm posting.

first q 26...find the time taken to produce one wavelength...for waveform P time is 4 seconds,,and for waveform Q time is 4.5 seconds..4,and 4.5 second represent 360 degrees...use options A,B,C,D time to find phase difference..for each waveform..and then subtract both of them...as for ..B..4.5s u'll get phase difference of 405 degrees for waveform p and 360 degree for waveform q ..405 - 360 equals 45 degreess..i.e 1/8 of cycle of the wave....for q 23...graph in which area under the graph is greatest that has highest elastic potential energy that is B if im not wrong...so its the answer....for 37..range is voltage accross 4kohm resistor..because q is fixed...and p can be made to move from top to Q...for 38 find effective resistance of two 200k ohm resistors and find voltage accross it....other 2 questions i cant help...

 

[Silent Hunter]

The P.E depends on the centre of gravity, not the height.

why? i mean formula is : pressure = height X density X g ? so the height does matters ?

 

[Ahmed Ali Akbar]

It is possible for a body to have acceleration when velocity is zero. e.g. what is the initial acceleration of a ball thrown from the top of a building? It's -9.81 but the velocity is zero and displacement is at its maximum. This is sort of comparable to SHM. Over here the restoring force (gravitational force) is at its maximum and since F = ma, this means that the acceleration is also at a maximum.

good...it really helped me..