Physics MCQs thread.

[arlery]

Oh I'm sorry I mistyped. I meant at 100% Power the voltage is 25000 V, so at 80% power, the voltage will be 20000 V.

 

[examfearz]

someone tellme how to do this...i cant figure out in how many boxes a wave is being completed.. :%)

 

[Abdulrab]

http://www.xtremepapers.me/CIE/index.ph ... 5_qp_1.pdf


PLEASE TELL ME HOW TO DO Q 31 !!! THANX

 

[arlery]

someone tellme how to do this...i cant figure out in how many boxes a wave is being completed.. :%)

since 8 waves - 6 boxes

therfore 1 wave -0.75 cm
0.75x 10ms/cm

7.5x10^-3 s

f =1/t = 1/(7.5x10^-3)

= 133.3 which is closest to 140.


Note: you can also use 0.7cm instead of 0.75

 

[arlery]

http://www.xtremepapers.me/CIE/index.php?dir=International%20A%20And%20AS%20Level/9702%20-%20Physics/&file=9702_w05_qp_1.pdf


PLEASE TELL ME HOW TO DO Q 31 !!! THANX

E =V/D = F/Q

So F = ( VxQ )/D

F = (200x1.6x10^-19)/(5x10^-3)

F = 6.4x10^-15

[A]

 

[gexceln]

Can't understand why the answer is A, help please

 

[arlery]

Can't understand why the answer is A, help please

Use the equation of motion d = ut + 0.5at^2

equation 1 : 40 = 12u + 72a

equation 2 : 80 = 18u + 162a

[I added the distances, so that initial speed of both equations will be same]

now solve these simultaneously, and you will get 0.37 m/s^2 as the answer.

 

[gexceln]

And this one.....answer is C but I thought momentum was conserved in inelastic collisions.

 

[beststriker]

i need help in june10/13 q29

 

[arlery]

i need help in june10/13 q29

If the electron was perpendicular to it, forces would not be acting on it. Whether the electron is stationary or moving, forces will be acting on it if it is parallel to plates.

Thus answer is C

Hope that helps.

 

[Zizu1992]

http://www.xtremepapers.me/CIE/Internat ... _qp_11.pdf
Please explain Question 26.

 

[arlery]

http://www.xtremepapers.me/CIE/International%20A%20And%20AS%20Level/9702%20-%20Physics/9702_w09_qp_11.pdf
Please explain Question 26.

Total maxima = 2 x highest maxima + 1

highest maxima = line spacing/wavelength

line spacing = 1/(300 x 10^-3)

highest maxima = (1/300x10^-3) /( 450 x 10^-9)

= 7.4 x 10^6

2(7.4 x 10^6) + 1 = 14.8 x 10^7

= 15 when you round it off

So answer is D

 

[Mobeen]

And this one.....answer is C but I thought momentum was conserved in inelastic collisions.

momentum is not conserved in inelastic!

 

[unique840]

And this one.....answer is C but I thought momentum was conserved in inelastic collisions.

momentum is not conserved in inelastic!

momentum is conserved in every situation. in inelastic collision, velocity and therefore kinetic energy is not conserved

 

[libra94]

And this one.....answer is C but I thought momentum was conserved in inelastic collisions.

momentum is not conserved in inelastic!

no yaar, momentum is consered in elastic and inelastic, kinetic energy is not conserved in inelastic

 

[arlery]

^ exactly. Momentum is conserved in every collision.

 

[beststriker]

help needed in nov09/11 q17..

 

[arlery]

help needed in nov09/11 q17..

It's C because since the molecules have same mass, and both are at same temperature, hence their velocities of molecules are also same. Therefore their kinetic energies are same.

 

[Mobeen]

oh sorry everybody! i got a lil confused! thanks for correcting!

 

[beststriker]

help in nov09/11 q22 ...