Physics: Post your doubts here!

[cowarrior]

HELP NEEDED GUYS....!!!! AS LEVEL PHYSICS

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s06_qp_1.pdf
CONFUSED IN QUESTIONS (37) PLEASE TELL ME IN DEATIL
(33) (31)(12) (24) (27) AND (28)

YOUR HELP WILL BE HUMBLY APPRECIATED..!!!!

 

[Daniyal23]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s06_qp_1.pdf q24..Answer is B Its an easy question but cant seem to figure it out. I know that Intensity is directly proportional to A^2 * F^2 but how to use this equation to get the correct answer?

 

[Taci12]

pls help me wid Q26...... http://www.xtremepapers.com/community/members/taci12.40527/
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_13.pdf
thanks

This is the same as question 27, p11 of the same session. Inboxed you already

 

[Taci12]

HELP NEEDED GUYS....!!!! AS LEVEL PHYSICS

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s06_qp_1.pdf
CONFUSED IN QUESTIONS (37) PLEASE TELL ME IN DEATIL
(33) (31)(12) (24) (27) AND (28)

YOUR HELP WILL BE HUMBLY APPRECIATED..!!!!

Question 12:
momentum is conserved
momentum = p =mass x velocity

initial total momentum = (3m x v) + (m x -2v) = mv

as they stick together after collision, their velocity after collision is the same

total final momentum = (3m + m) x velocity = mv
4m x velocity = mv
velocity = v/4

Question 24:

if frequency is halved, the period is doubled as f=1/T
--> time taken for 1 complete cycle is doubled

intensity ∝ (amplitude^2)
amplitude ∝ √intensity

if intensity is doubled, thus the new amplitude is √2= 1.4

thus it's option B

 

[Taci12]

HELP NEEDED GUYS....!!!! AS LEVEL PHYSICS

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s06_qp_1.pdf
CONFUSED IN QUESTIONS (37) PLEASE TELL ME IN DEATIL
(33) (31)(12) (24) (27) AND (28)

YOUR HELP WILL BE HUMBLY APPRECIATED..!!!!

Question 27:
always, to calculate number of visible orders/images
d sin θ= nλ
d=1/N

sin θ/N= nλ

sin θ=nλN
for all orders except zero order

sin θ<1
nλN<1
n<1/(λN)

If we increase the number of lines per m, i.e N,
number of visible orders decreases

As for the angle:
sin θ=nλN
Increase N, sin θ increases.
As θ is acute, when sin θ increases, so does θ

so answer is B

Question 28:
fringe width= β = λD/d

λ= wavelength, D= distance between screen and double slit arrangement, d= separation of slits

If we halve d, β is doubled,i.e takes on a value of 8 mm

Then D is doubled, β is doubled again, β= 2 x 8 = 16 mm

Question 31:
Q=charge
Q=It
Q=ne
ne=It
rate of flow of electrons = n/t = I/e
= 4.8 / (1.6 x 10^-19)
= 3.0 x 10^19

Current flows from higher potential to lower potential, and electrons flow in the opposite direction.
Hence electrons flow from negative electrode of cell to positive electrode, i.e Y to X

 

[Taci12]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s06_qp_1.pdf
CONFUSED IN QUESTIONS (37) PLEASE TELL ME IN DEATIL
(33) (31)(12) (24) (27) AND (28)

YOUR HELP WILL BE HUMBLY APPRECIATED..!!!! [/quote]

Question 33:
-->use potential divider formula
p.d between X and P=V1= [500/(500+1000)] x 12 = -4.0 V
p.d between P and Y =V2 = [2000/(2000+1000)] x 12 = 8.0 V

total p.d between X and Y = 4.0V

 

[queen of the legend]

paper 1 doubts
please help

(All may/june)

03: 11, 13, 15, 17 , 22, 40

04: 6, 11, 14, 16, 33 ...(why 16 is not d?)

05 : 4, 7, 11, 13, 15, 24, 32, 33, 37.

07: 27, 33 , 40

08: 16, 24, 23, 26, 32, 34

 

[Alice123]

This is the same as question 27, p11 of the same session. Inboxed you already

ohhh!!! thanks

 

[cowarrior]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s06_qp_1.pdf
CONFUSED IN QUESTIONS (37) PLEASE TELL ME IN DEATIL
(33) (31)(12) (24) (27) AND (28)

YOUR HELP WILL BE HUMBLY APPRECIATED..!!!!

Question 33:
-->use potential divider formula
p.d between X and P=V1= [500/(500+1000)] x 12 = -4.0 V
p.d between P and Y =V2 = [2000/(2000+1000)] x 12 = 8.0 V

total p.d between X and Y = 4.0V[/quote]
A very thanx to you........

 

[cowarrior]

Question 12:
momentum is conserved
momentum = p =mass x velocity

initial total momentum = (3m x v) + (m x -2v) = mv

as they stick together after collision, their velocity after collision is the same

total final momentum = (3m + m) x velocity = mv
4m x velocity = mv
velocity = v/4

Question 24:

if frequency is halved, the period is doubled as f=1/T
--> time taken for 1 complete cycle is doubled

intensity ∝ (amplitude^2)
amplitude ∝ √intensity

if intensity is doubled, thus the new amplitude is √2= 1.4

thus it's option B

ok what about question (37)??

 

[aniroula]

can some one help me with these questions.. thanks in advance
may june 2013 qp 11
no 19,20 $27..

 

[Alice123]

can some one help me with these questions.. thanks in advance
may june 2013 qp 11
no 19,20 $27..

this is 2012

 

[aniroula]

this is 2012

sorry dude that is may june 2010

 

[Alice123]

sorry dude that is may june 2010

19. E=Stress/Strain =3x1o^8/5% =3x10^8/0.05=6x10^9

 

[Alice123]

this is 2012

20. Spring constant k=F/e.... think abt da gradient of the graph.... k=6/(1oo-70)x10^-3=200Nm^-1

 

[Alice123]

can some one help me with these questions.. thanks in advance
may june 2013 qp 11
no 19,20 $27..

27. Work done in a circular path=0

 

[Taci12]

HELP NEEDED GUYS....!!!! AS LEVEL PHYSICS

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s06_qp_1.pdf
CONFUSED IN QUESTIONS (37) PLEASE TELL ME IN DEATIL
(33) (31)(12) (24) (27) AND (28)

YOUR HELP WILL BE HUMBLY APPRECIATED..!!!!

Question 37:
e.m.f = sum of p.d
As e.m.f is constant, for p.d across thermistor to be maximum, p.d across LDR must be minimum.

for thermistor: decrease tem, resistance increases, p.d increases

for LDR ; increase light intensity, resistance decreases, p.d decreases

Answer is B

 

[sma786]

Anybody has any good notes for uncertainity ??

 

[Taci12]

Anybody has any good notes for uncertainity ??

Not exactly notes, but it may help for calculations:
1. if the given equation is a sum or subtraction, add absolute uncertainties
2. if given equation is a product or quotient (multiplication or division), add fractional uncertainties. In this case you would obtain the fractional uncertainty for the final answer. To obtain the absolute uncertainty, just multiply the fractional by the actual value of the answer.

absolute uncertainty is Δx and fractional uncertainty is Δx/x.

For values raised to powers, e.g x^5
the fractional uncertainty = fractional uncertainty of x x (power to which x is raised)
Δx^5/x^5 = 5 x (Δx/x)

 

[Alice123]

pls solv no 9..... http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_w10_qp_11.pdf
http://www.xtremepapers.com/community/members/taci12.40527/
thanks