Physics: Post your doubts here!

[Haya Ahmed]

Q6d there is something wrong with the voltage it is not divided equally you know the formula R=V/I if you make V the subject R*I=V it means there is something wrong with the resistance in the wire or the current
Q7 the alpha particle should be moving ie it should have a kinetic energy so it goes and hits the nitrogen 14 nucleus like if you keep an alpha particle next to a nitrogen it will just push it away its just the alpha particles scattering experiment with a Nitrogen nucleus instead of a gold


Q7 (a) they have mentioned all the lamps are similar and therefor they all have the same resistance but one of them is faulty
by the 2nd reading from the table you might know A=15 ohms and so you can assume B and C are also suppose to be 15 but one of them is faulty
by the third reading you can confirm that B is 15 cause A and B are in series and the total resistance is 30
left with C which is most probably the faulty one but wait find the resistance if C was not faulty it would be 22.5 but the answer says 15
shorted lamps are lamps going to earth short circuited faulty

I used to hate this questions never used to get them but they make sense now
I always like to make a figure on the side and work on it rather than work on the fig given but you make the call

Thanks a lot can you answer this question too ! ^^

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w12_qp_22.pdf
Q5 (b) with explaination

 

[Thought blocker]

please can someone explain the q 1d) from: papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w11_qp_23.pdf

please answer as soon as possible. thnx in advance.

Hope all thing is Visible

 

[_Ahmad]

Describe an experiment to determine the wavelength of sound in air using stationary
waves. Include a diagram of the apparatus in your answer.

 

[Thought blocker]

Thanks a lot can you answer this question too ! ^^

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w12_qp_22.pdf
Q5 (b) with explaination

Here you go
pd across Ac 40/100 * 12 = 4.8
pd across Ad 4/6 * 12 = 8
8-4.8 =3.2

 

[ZaqZainab]

Thanks a lot can you answer this question too ! ^^

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w12_qp_22.pdf
Q5 (b) with explaination

1 meter of AD has a resistance of 10 ohms
40 cm (0.4m) will have 4 ohms of resistance (cross multiply)
P.D=R*I
the current in AC I=I2 which you found in (a) so I2=1.2
and so the p.d at AC=1.2*4=4.8
the resistace across AD=4 ohms
and the current is I3 which is 2
so p.d=2*4=8
8-4.8=3.2V

 

[Talha Irfan]

Describe an experiment to determine the wavelength of sound in air using stationary
waves. Include a diagram of the apparatus in your answer.

Apparatus :
Loudspeaker (switched on)
Glass tube with an open end
Detector

Method :

1) Place the loudspeaker infront of the open end of the glass tube
2) Move the detector along the glass tube and measure the distance between two CONSECUTIVE regions which show zero/min intensity on the detector
3) Take set of values and average them to eliminate random error
4) Finally, equate the distance measured with 1/2(lambda)

so lambda (wavelength) = 2d (unit specified)

 

[Snowysangel]

We can answer this by thinking about the energy which is carried away by the particles (alpha or beta) and electromagnetic radiation (gamma) produced in the decay.Albert Einstein realised that we can think of energy as having mass. So if the mass of the nucleus decreases we must look around and find the energy which is carrying away this mass.The greater the apparent loss in mass the greater the amount of energy which is escaping.
To sum up we talk about "mass-energy" . In any closed system the total amount of mass-energy is conserved. If the mass goes down energy goes up and vice versa, but the total is constant

But the mass does remain the same, or at least approximately the same right

 

[Wolfgangs]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s11_ms_21.pdf

How to solve Q5 b? I'm still kinda confused

 

[Thought blocker]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_ms_21.pdf

How to solve Q5 b? I'm still kinda confused

Note that we r asked to find I2 i.e. the current across a fixed resistor..
so maximum current will be:- V/R= 12/6 = 2.0 A
and i think that the minimum current value is zero just bcuz if we take the value of the variable resistor less than the value of fixed resistor then all the current will flow through the low resistance loop giving zero reading on the ammeter for the second loop

 

[MiniSacBall]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s05_qp_2.pdf

q6 b)

 

[Thought blocker]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s05_qp_2.pdf

q6 b)

i just know part ii)
force=electric field strength multiplies charege
charge is given and we calculated the electric field strength
find out the force
f=qe(1.2*10^-15*2*10^3)

 

[MiniSacBall]

i just know part ii)
force=electric field strength multiplies charege
charge is given and we calculated the electric field strength
find out the force
f=qe(1.2*10^-15*2*10^3)

Thank you, but i wanted the (i) part and (iv)

 

[Thought blocker]

Thank you, but i wanted the (i) part and (iv)

Idk, sorry. Suchal Riaz thementor

 

[_Ahmad]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s12_qp_22.pdf

please help
Q6 b ii)

 

[_Ahmad]

sorry.
Q6 c ii)

 

[Thought blocker]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s12_qp_22.pdf

please help
Q6 b ii)

Apparatus :
Loudspeaker (switched on)
Glass tube with an open end
Detector

Method :

1) Place the loudspeaker infront of the open end of the glass tube
2) Move the detector along the glass tube and measure the distance between two CONSECUTIVE regions which show zero/min intensity on the detector
3) Take set of values and average them to eliminate random error
4) Finally, equate the distance measured with 1/2(lambda)

so lambda (wavelength) = 2d (unit specified)

 

[_Ahmad]

Can you please help with Q6 c ii) of the same paper

 

[Thought blocker]

Can you please help with Q6 c ii) of the same paper

Here if you can not understand my writings there
Distance b/w two nodes is lambda/2 ; and length of nodes was 34
hence 34 * 2 = lambda = 68 cm , we take SI units, hence 0.68 m
Now, As f = v / lambda ; 340 / 0.68 = 500 Hz
Hope you got it

Alternative way :¬

Distance between node and antinode is lambda / 4
hence then length is 17 ; now 17 * 4 = lambda = 68 cm i.e 0.68 m
now same thing f = 340 / 0.68 = 500 Hz

Anyway you can do it

 

[Mohammed salik]

Idk, sorry. Suchal Riaz thementor

Thank you, but i wanted the (i) part and (iv)

Look for Part (i) The Electric field Is The direction where Positive Charge Moves.

And part (iv) :- It Would Rotate due to Torque Produced. .(Plus forces are oppsite and equal) To Align with the electric field .. The rotation would be Clockwise.. Because Positive End would be Towards The direction of Electric field.!

 

[Thought blocker]

Can you please help with Q6 c ii) of the same paper

If you are weak in waves, here you go for hand written notes And other note too, that is not hand written but useful
Hope, you get good grades this session

*Nazar na lagey kisiki*