As physics p1 MCQS YEARLY ONLY.

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q15) F=kv and F=mg are same
so kv=mg so v=mg/k
ke=1/2 m x v^2 substitute v and u get m^3 x g^2/2k^2
pls explain these ones:
nov_10_13: 2, 12, 14(some explain this before but i didn't get it), 25(answer why not D), 31

june_11_12: 6(why not B), 16, 17, 29, 31

just one more paper after this INSHA ALAH

JAZAK ALLAH!
 
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pls explain these ones:
nov_10_13: 2, 12, 14(some explain this before but i didn't get it), 25(answer why not D), 31

june_11_12: 6(why not B), 16, 17, 29, 31

just one more paper after this INSHA ALAH

JAZAK ALLAH!
nov_10_13: 2 cant help u in this question u r suppose to noe dem by heart

12)there is a formula force=momentum/time so gradient=y/x so answer is A

14)so imagine wat force is acting on P and in which direction the same with Q and W the weight always acts downwards now for O the force of the wall is acting on it so arrow points left and on Q force of ground acts on it so arrow points upwards

25)they are inversely proportional because as delta increases l increases
 
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Is this is all u can do..Where is november 2003..well ill tell u something....u made this thread so ur the one who must start to help..if u have any doubts ask..if u want to help, pls do...but dont act as if we work for u and that we must post every year..we did enogh job..if u want it go look for it
its my great idea that you guys are working on. if you don't wanna help then don't bother. i didn't beg you to do all papers. you did it with your own wish. stop crying now.
 
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November 2007

1-C
Use base units and equate both sides.

2-A
Learn the approximations.

3-B
Resultant force is always is opposite direction of its two components in the triangle of forces.

4-D
Precision is the closeness of measured values.
Accuracy is the closeness of measured values to actual value.

5-C
P = fv
f = ma and v = s/t

P = add up all the % uncertainties.
%P = 0.1 + 1 + 1.5 + .5
= 3.1 %

6-A
Due to zero error, the initial value of angle of deflection will be greater than zero at zero current.

7-A
Basic concept that g gravity is the acceleration of free fall.

8-D
The gradient of velocity-time graph is acceleration.


9-B

Area of distance above x axis - area of distance below x axis.
(0.5 * 3 * 30) - (.5 * 2 * 20)
= 25 m

10-D

Driving force - frictional force = ma
12- Fre = 0.6(4)
12- 0.6(4) = Fre
9.6 N = Fre

11- B
View attachment 12245

12-A
Since the parachutist is falling, height is decreasing over time.
Gradient of distance-time graph is speed.

13-C
Use head to tail method.

14-D
At midpoint, d = 0.8/2 = 0.4m
Moment = F*d
12 = F * 0.4
30 N = F

15-B
Initial K.E. - Final K.E.
(0.5* 1000 *25^2) - (0.5 * 1000 * 5^2)
300 000 J
300 kJ

16 - C
At max d, K.E. = minimum and elastic potential energy = maximum.

17-C
Density = mass/volume
Hence higher density means a higher mass, hence more no. of atoms.
So MpNp > MqNq

18-A
Height at surface =?
Pressure = density * g* h
100 000= 1030 * 9.81 * h
9.896 m = h1

Height at 450 kPa =?
450 000 = 1030 * 9.81 * h
44.535 = h2

Therefore height below surface = 44.535 - 9.896
=34.639 ~ 34.6m

19-B
Basic definition.

20- A
Strain energy = 1/2 * F * extension
= 0.5 * 25 * (0.4 - 0.2)
= 2.5 J

21- B
View attachment 12247

22- B
Learn the wavelengths.

23- B
Max speed = 2pii *a *f
f = ?
s = f* lamda
8 = f (50)
0.16 Hz = f

Max speed = 2pii * 2 * 0.16
=2 m/s
Max K.E. = .5 m* v^2 = 0.5 * 2 * 10^-3 * 2^2
= 4 mJ

24-D
x = lamda * D/ a

Hence increasing the lamda, increases x, that is the fringe separation.

25-B

d sin theta = n* lamda
At n = 3, theta = 45 degrees
d sin45 = 3*lamdaa
0.7 d = 3 lamda

and max angle = 90 , so n =?
d sin90 = n*lamdaa
d = n* lamda

Using the ratio method:
If 0.7d = 3 lamda
1 d =?
cross multiply and you get n as 4.25 hence rounding it off to 4th order.

26- C
Since electric field direction is from higher p.d./charge to lower p.d./charge the electron will be attracted towards the more positively charged plate (or direction) hence to the left.

27-D
Direction of electric field is away from positive charge.

28-B
E = V*Q
E/Q = V

29-D

P = V^2/R
P = 12^2/Rx and P = 6^2/Ry
Rx = 144/P and Ry = 36/P

Rx/Ry = 144/P divided by 36/P
Rx/Ry = 144/36 = 4

30-D

V = IR
6 = I (10 +10)
0.3 A = I

Q = It
0.3 * 60 = 18 C

31-A

View attachment 12248

32-A

Basic concept of L.D.R.; when light intensity increases, resistance decreases hence voltage decreases too.

33-D
V in = R1/T.R. * V out
4.8 = 10/25 * V out
4.8* 25/10 = V out
12 = V out

34-D
Using the ratio method:
If 1.1 V - 0.7 m
? - 0.9 m
x = 0.9* 1.1/ .7
x = 1.4 V

35-A
The readings won't change because the set up is the same.

36- C
Charge is same since proton no. is same, but mass differs since no. of neutrons differs.

37- C
Basic concept.

38-C
The alpha scattering experiment proves the small size of a gold nucleus.

39-B
In a beta emission, the nucleon no. remains same but the proton no. increases by 1
For 2 beta emissions, proton no will increase by 2 hence 40 +2 = 42

40-A
Momentum = mv, greater m = greater momentum.
hence the particle with the greatest mass from all the choices is A, an alpha particle.
In q.6 the reason u gave makes both A and B the correct ans. How to know that A is the correct one?
 
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