Physics MCQs thread.

[mickysharif]

Help please, answer is A but I don't get why it is. C seems a better option to me.

you must be thinking that it goes up and then comes down, but notice that the x axis says that the height is unceasing so it is only going up. and when going up the potential increases.

 

[arlery]

because they never mentioned the downward motion of the object.

 

[nerd007]

http://www.xtremepapers.me/CIE/Internat ... 5_qp_1.pdf

Question number 13? please help.. =(

 

[nerd007]

http://www.xtremepapers.me/CIE/International%20A%20And%20AS%20Level/9702%20-%20Physics/9702_s05_qp_1.pdf

Question number 13? please help.. =(

do you take 2 as the distance?

 

[mickysharif]

http://www.xtremepapers.me/CIE/International%20A%20And%20AS%20Level/9702%20-%20Physics/9702_s05_qp_1.pdf

Question number 13? please help.. =(

5N force will cause a momentum that is over a distance 402 - 2 and 5x2 = 10. where has the 10nm will also cause anticlockwise wise rotation which will be over a distance of 2m so 2 x 10 = 20 , thus the total anti clockwise = 10 + 20 = 30 and anti clockwise will be over a distance 3 and its 20 n so it will be 20 x 3 - 60 , so 60-30 = 30Nm is the answer [in anti clockwise]

 

[arlery]

^ I don't get it =S

 

[nidzzz09]

Okay 0/n 2008 question 1 okay i gt the frequency n den wat do we do http://www.xtremepapers.me/CIE/Internat ... 8_qp_1.pdf

 

[mickysharif]

^ I don't get it =S

try doing it again this time keep in mind u have to take the perpendicular distance, i recommend that you extend each force line first and then see which is the perpendicular distance. also 10N force will cause anticlockwise motion because of the shape of the figure.

 

[mickysharif]

Okay 0/n 2008 question 1 okay i gt the frequency n den wat do we do http://www.xtremepapers.me/CIE/Internat ... 8_qp_1.pdf

you don't need the frequency all you need is to find the distance light travels in one second which is 3 x 10^8 as speed is d/t and when t=1 d = 3x10^8. now that you have the lenght you have to press it as number of wavelenghts, to find how many wavelenghts are needed to cover this distance we divide distance by wavelenght. 3x10^8 / 600nm . 600 nanometers = 6.0 × 10^-7 meters (3x10^8)/(6.0 × 10^-7) = answer

 

[mickysharif]

the answer is A can someone explain why..

 

[arlery]

yeah I didn't understand that either.

Which year is that?

 

[mickysharif]

08 may/june Q16.... We really need some intelligent person here lol

 

[arlery]

^ XD lol

 

[gexceln]

the answer is A can someone explain why..

The answer is A because you need the displacement in the direction of the electric field which is s. It decreases because the charge moves in the direction of the field hence decreasing it potential energy in doing the work Fs.

 

[mickysharif]

the answer is A can someone explain why..

The answer is A because you need the displacement in the direction of the electric field which is s. It decreases because the charge moves in the direction of the field hence decreasing it potential energy in doing the work Fs.

thankyou, it makes sense now since i did this other question that also said the direction should be parallel to the direction of force..so yeah. thankq


Can you please try solving + explaining this other as well =

A moving body undergoes uniform acceleration while travelling in a straight line between points
X, Y and Z. The distances XY and YZ are both 40 m. The time to travel from X to Y is 12 s and
from Y to Z is 6.0 s.
What is the acceleration of the body?
A 0.37 B) 0.49 C) 0.56 D) 1.1

 

[arlery]

Why is the answer B?

 

[arlery]

the answer is A can someone explain why..

The answer is A because you need the displacement in the direction of the electric field which is s. It decreases because the charge moves in the direction of the field hence decreasing it potential energy in doing the work Fs.

thankyou, it makes sense now since i did this other question that also said the direction should be parallel to the direction of force..so yeah. thankq


Can you please try solving + explaining this other as well =

A moving body undergoes uniform acceleration while travelling in a straight line between points
X, Y and Z. The distances XY and YZ are both 40 m. The time to travel from X to Y is 12 s and
from Y to Z is 6.0 s.
What is the acceleration of the body?
A 0.37 B) 0.49 C) 0.56 D) 1.1

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]

Why is the answer B?

Effective resistance = (1/(500+1000) + 1/(2000 +1000))*-1 = 1000

I = V/R = 12/1000 =0.012

Current splits in proportion to resistances of branches, 0.008 through the 500 and 100 branch and 0.004 through the 1000 and 2000 branch.

v= IR

For 500 ohm resistor => V= 0.008*500 = 4V
For 2000 ohm resistor => V = 0.004*2000 = 8V

p.d = 8V-4V = 4V

Hence B

 

[kakarocks]

the answer is A can someone explain why..

It's really touch and go with A2 syllabus here , First a SHM question and now this . LOL Cie don't want their student's to pass .Just Remember that



if a positive charge moves away from a positive charge it looses E.P.E why ? Because when it was brought to that position Work had to be done on it and it gained P.E equal to that w.d . In case of a fixed negative charge and movable Positive one , Work has to be done to move them apart so they gain E.P.E and Loose it when they come Closer!

 

[yubakkk]

ok guys all the best for ur exam...........