IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: cs on September 14, 2010, 11:08:42 am

Title: CIE physics paper 2
Post by: cs on September 14, 2010, 11:08:42 am
Nov 2002

Q6) why is the arrow in upward direction ( as what i noticed, its from higher potential to lower), any one care to explain, here's the question attached with answer
Title: Re: CIE physics paper 2
Post by: nid404 on September 14, 2010, 04:16:36 pm
 electron has a negative charge. Direction of force on electron will be towards the positive plate.
Title: Re: CIE physics paper 2
Post by: cs on September 15, 2010, 04:05:11 am
electron has a negative charge. Direction of force on electron will be towards the positive plate.


+rep
Title: Re: CIE physics paper 2
Post by: *Hope* on September 15, 2010, 07:15:34 am
Unlike charges attract and like charges repel :)
Title: Re: CIE physics paper 2
Post by: Deadly_king on September 15, 2010, 07:15:56 am
Nov 2002

Q6) why is the arrow in upward direction ( as what i noticed, its from higher potential to lower), any one care to explain, here's the question attached with answer

Actually the electric field is downwards from higher potential to lower potential. When the electron penetrates the electric field perpendicularly an electric force acts on it. This electric force is always opposite to the direction of the electric field for an electron.

Therefore the electron proceeds through the electric field between the two plates with a slight parabolic path towards the positively charged metal plate. Then it exits the field in a a straight line tangential to the point it exits the field.

But its easier to understand the way Garfield explained, i.e being negatively charge it is attracted to the positively charged metal plate.
Title: Re: CIE physics paper 2
Post by: *Hope* on September 15, 2010, 07:17:04 am
+rep Deadly_king :D Very informative mA :)
Title: Re: CIE physics paper 2
Post by: Deadly_king on September 15, 2010, 07:24:33 am
+rep Deadly_king :D Very informative mA :)

Thanks.......though you said almost the same thing in only one line :P
Title: Re: CIE physics paper 2
Post by: *Hope* on September 15, 2010, 07:29:27 am
Thanks.......though you said almost the same thing in only one line :P
LOL! Now Cs has more ways to learn it..the easy and the hard way :P ;)

mA! Keep up this amazing work :D
Title: Re: CIE physics paper 2
Post by: Deadly_king on September 15, 2010, 07:35:20 am
LOL! Now Cs has more ways to learn it..the easy and the hard way :P ;)

mA! Keep up this amazing work :D

Hahaha........yeah i guess so  ::)

Sure........i actually love helping and it also helps me revise :)
Title: Re: CIE physics paper 2
Post by: *Hope* on September 15, 2010, 07:39:06 am
I really am proud that this forum has very helping members like you :D

And insA Allah will help you as you are helping others..and yea trueeee...when you explain and help someone..the info sticks to ur mind and reminds you if u know the topic well or not insA :D
Title: Re: CIE physics paper 2
Post by: Deadly_king on September 15, 2010, 07:50:24 am
You know what??

The way you express yourself actually makes me want to help even more.........its very encouraging :)

Its a pleasure to be acquainted to such a nice person............you'll certainly be a good mod :)
Title: Re: CIE physics paper 2
Post by: cs on September 15, 2010, 08:06:12 am
Thanks to all of you.. I am really glad that i found you guys in this forum.. :)
Title: Re: CIE physics paper 2
Post by: cs on September 15, 2010, 08:08:14 am
Thanks to all of you.. I am really glad that i found you guys in this forum.. :)
although you guys made me feel that i am so weak in physics.. ;D
Title: Re: CIE physics paper 2
Post by: Deadly_king on September 15, 2010, 08:23:38 am


Nan.......that was not our intention! Far from that we'll help you in any way we can :)

There's no shame in not knowing something ;)
Title: Re: CIE physics paper 2
Post by: *Hope* on September 15, 2010, 09:19:13 pm
You know what??

The way you express yourself actually makes me want to help even more.........its very encouraging :)

Its a pleasure to be acquainted to such a nice person............you'll certainly be a good mod :)
Thank you..I am flattered :D :-[ :P I like that I encourage to help :D
Title: Re: CIE physics paper 2
Post by: Deadly_king on September 20, 2010, 11:23:09 am
Thank you..I am flattered :D :-[ :P I like that I encourage to help :D

Hehe........i hope that 1 day i may be as encouraging as you are to others :)
Title: Re: CIE physics paper 2
Post by: Greed444 on September 24, 2010, 05:55:45 pm
can someone help explain what is phase angle 60 degree as in the OCT/NOV 2002 Q5
it would be great if someone can show me how to do the Q5b(i) too :)
Title: Re: CIE physics paper 2
Post by: Deadly_king on September 24, 2010, 06:01:25 pm
can someone help explain what is phase angle 60 degree as in the OCT/NOV 2002 Q5
it would be great if someone can show me how to do the Q5b(i) too :)

By a phase angle of 60 degrees.......it meant that the wave T2 would be moving 60 degrees faster.

In other words, when wave T1 is at maximum amplitude at time t=0, wave T2 will be at maximum amplitude at time t=0.5

But both waves will be having same frequency, wavelength and period.
60 degrees is the phase angle. To be able to do Q5b(i) you should convert the phase angle to the time difference sine the graph is one of X against time.
Phase angle = (delta T)/T * 360

From the graph it is noted that period T= 3s.
Hence delta T will be 0.5s.

You just need to draw a wave with same amplitude, same frequency and wavelength........but which is just 0.5s faster.

Hope you understood........if not let me know and i'll try to be clearer :)
Title: Re: CIE physics paper 2
Post by: S.M.A.T on September 24, 2010, 06:19:54 pm
Keep it up DK :D :D


+rep
Title: Re: CIE physics paper 2
Post by: Greed444 on September 25, 2010, 06:42:50 am
By a phase angle of 60 degrees.......it meant that the wave T2 would be moving 60 degrees faster.

In other words, when wave T1 is at maximum amplitude at time t=0, wave T2 will be at maximum amplitude at time t=0.5

But both waves will be having same frequency, wavelength and period.
60 degrees is the phase angle. To be able to do Q5b(i) you should convert the phase angle to the time difference sine the graph is one of X against time.
Phase angle = (delta T)/T * 360

From the graph it is noted that period T= 3s.
Hence delta T will be 0.5s.

You just need to draw a wave with same amplitude, same frequency and wavelength........but which is just 0.5s faster.

Hope you understood........if not let me know and i'll try to be clearer :)

Thank you DK ^^ your explanations are crystal clear! :D
Title: Re: CIE physics paper 2
Post by: Deadly_king on September 25, 2010, 07:02:38 am
You are welcome :)

Glad to have been able to clear your doubts  ;)

Thanks Asif  :D
Title: Re: CIE physics paper 2
Post by: Greed444 on October 04, 2010, 01:31:00 pm
i have a problem on O/N 2004 paper 2
its on Q6b (ii) & c
Title: Re: CIE physics paper 2
Post by: S.M.A.T on October 04, 2010, 05:53:24 pm
b ii)Potential difference acrooss C&R are same as emf(because of parallel connection)

From the graph:
when v=2V
current in R=1.3A
current in C=0.75A
therefore,current in the battery+1.3+0.75=2.05A
c)The current is same in both R&C as they are connected in series.But the potential difference across C is higher than R.Since power=VI,therefore component c will dissipate thermal energy at a greater rate
Title: Re: CIE physics paper 2
Post by: Greed444 on October 05, 2010, 01:16:03 pm
many thanks asif! :D
Title: Re: CIE physics paper 2
Post by: S.M.A.T on October 06, 2010, 06:24:09 am
U WELCOME ;D