kindly explain me Q13 and Q19 ASAPoh it was a tough one!!Here is the June 2009..

1: D...basic stuff

2: C...opp/adj = tan ( theta) so opp=adj tan(theta) = 20tan( 30) =11.5

3: B...the readings are -6.5 and 14...so 14- (-6.05) so 20.5

4: B...P=VI= 1.2 x 0.48

5: D..he siad terminal velocity means velocity is constant and so d must have a constant increase..all other 3 graphs have d starts to decrease so D is correct

6: C...obvious from the graph

7: A...basic stuff...

8: C...air resistance is neglected so constant horizontal velocity and constant vertical acceleration

9: B...rate of changeof momentum= mv-mu, so (0.1 x -30) - (0.1 x 20)= -5....we used - 30 because it was travelling in the opposite direction

10: C...the momentum of body m must equal the momentum of body 2m..this means that if body m has half the mass so it must have double the velocity so ratio of kinetic energy of m /2m = ( 0.5 m x 2v^2)/ (0.5 x 2m x v^2) so it will be 2/1

11: A..the ball will not fall diagonaly..so S must equal to Q...according to the question..he didnt say if the ball will flought orwill sink so i thought that the upthrust is the difference of the pressure betwwn the water and the weight of the object so R > than P

12: D...he said it is falling with uniform velocity so no acceleration so no resultant force..and he said it is still falling horizontally so no resultant torque..so the conditions for equillibrium are found

13:ooh ill blow from this one and i may need some 1 to explain it to me..thnx in advance

14: C...K= F/v^2 means F/v x v and F = P/v so K = P/v/ (v x v) so K=(P/v) x v^-2 and then K = P x v^-1 x v^-2 so P x v^-3 means P/v^

15: B...container X lost half of the water means it lost half the height and half THE MASS so m/2 g h/2 so 2 x 2=4 so ( mgh )/4

16 and 17 are basic and simple stuff

18: D...at first the pressure was pgh..then the height was raised by another h so pgh + h = pg2h

19: A...B and C are wrong because they are brittle so they will break..steel is a mixture of 2 substances so it have the melting point of 2 substances which are iron and carbon...so aluminium is a single metal susbtance and so it will melt first

20: D...young modulus is ( Fl)/ (Ae) he said they are the same material so same young modulus..and same extension..then tension is the F so F= A/l ( no need for the young modulus and the extensoin so ...( l/A) /( 2l /0.5A) continue and u will get 4 / 1

21: A...if u draw a straight line from the origin to the same point the drawn graph reaches and took 0.5 x 17 x 0.30 it will equal 2.7..and the graph shows that thre is much spce between it and the line we drew so it must be < 2.7..so C and are wrong..B is wrong because it is about or approximatley the same as 2.7 so it alo must be less than 2.6 so A

22 and 23 are also basic and simple stuff

24: B...the distance between 2 adjacent nodes orantinodes is half a wavelength..so the distance between a node and an anti node is the quarter

25: A..N lines per metre means 1/N...then substituting into the equation it will be (1/N) sin (theta)= n ( lambda)

26: B...as shown 1.5 lambda = 2.1m so one wavelength is 1.4..then v=f lambda = 80 x 1.4 = 112

27: A...both are attracted to the +ve plate so both are -ve

28: B...E is proportional to V so doubling V doubles E......E is inverseley proportional to d so halfing d doubles E so B

29: D...v^2 = 2as..a=F/m so v^2 = 2 x (F/m) s and F= EQ means Ee as in the question..so v^2/2 = (Ee/m) s continue and u will get D

30: A...I=Q/t..simple question

31: D...W=QV so Q= 7.2 x 10^4 / 12 = 6000

32: A...basic EMF definition

33: B....I = E1 - E2 / R so ( 3 - 1.2) / 9 = 0.2

34: D..simple question..total resistorsin series = R1+R2+R3..in parrallel...1/Rt= 1/R1 + 1/R2 + 1/R3

35: D...light intensity and temperature increases so resistance in the LDR and thermistor decrease so the other resistor resistance increases

36 and 37 are simple questoins

38: C...just subtract the proton number from the nucleon number of each

39: C...simple question

40: D...he said a neutron so proton number must be zero and nucleon number is one