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Author Topic: physics doubt  (Read 3615 times)

Offline T.Q

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physics doubt
« on: April 27, 2010, 09:47:20 am »
Three identical resistors are connected across a potential difference V so that one of them is in parallel with the other two which are connected in series. The power dissipated through the first one, compared to the power dissipated by each of the other two, is approximately

A   the same
B   half as much
C   twice as much
D   four times as much



which one is the answer & explain why ?
« Last Edit: April 27, 2010, 09:57:37 am by T.Q »
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~ A.F ~

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Re: physics doubt
« Reply #1 on: April 27, 2010, 09:57:19 am »
Quote from: T.Q on April 27, 2010, 09:47:20 am
Three identical resistors are connected across a potential difference V so that one of them is in parallel with the other two which are connected in series. The power dissipated through the first one, compared to the power dissipated by each of the other two, is approximately

A   the same
B   half as much
C   twice as much
D   four times as much



explain why ?

The answer is D..four times as much..

here's the deal:

Voltage for the lone resistor= V..and voltage for both of the resistors connected in parallel is also V..right?

now the volatage for each of the resistors in series = 0.5V..right?

P=V2 /R

therefore, for lone resistor P=V2 /R

for each of the  resistors in series: P= (0.5V)2 /R= 0.25V2 /R

1/0.25=4.

got that?  ::)
« Last Edit: April 27, 2010, 09:59:40 am by ~ A.F ~ »
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Offline T.Q

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Re: physics doubt
« Reply #2 on: April 27, 2010, 10:04:14 am »
ya i got it

thanx  :)

+rep
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No Matter What Happens In Life , Just Don't Lose Hope :)

~ A.F ~

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Re: physics doubt
« Reply #3 on: April 27, 2010, 10:08:50 am »
Any time :)

and Thanks 4 the +rep. :D
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nid404

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Re: physics doubt
« Reply #4 on: April 27, 2010, 10:16:44 am »
A.F- I told you..you are mind-blasting! :)
+ rep
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~ A.F ~

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Re: physics doubt
« Reply #5 on: April 27, 2010, 10:19:53 am »
Oh  :-[  lol

Thanks Nid! :D
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Offline halosh92

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Re: physics doubt
« Reply #6 on: April 27, 2010, 06:11:25 pm »
anyone has the ms for physics AS cie 2002 nov
plzzzzzzzzzzz rili urgent
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everyday we wake up is a miracle, then how do we say miracles dont happen?????

Offline Saladin

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Re: physics doubt
« Reply #7 on: April 27, 2010, 06:31:36 pm »
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Offline halosh92

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Re: physics doubt
« Reply #8 on: April 27, 2010, 06:37:27 pm »
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everyday we wake up is a miracle, then how do we say miracles dont happen?????

Offline Saladin

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Re: physics doubt
« Reply #9 on: April 29, 2010, 12:08:14 pm »
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Offline sweetie

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Re: physics doubt
« Reply #10 on: April 29, 2010, 02:57:22 pm »
in may06 p1 of phy. cie, why did we split the area inta a trapezium and a triangle instead of just considering the area of the whole triangle????

cud sum1 also xplain Q9. of the same year??????
« Last Edit: April 29, 2010, 03:00:02 pm by sweetie »
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nid404

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Re: physics doubt
« Reply #11 on: April 29, 2010, 03:45:31 pm »
Q9) ohk a spring is oscillating up and down... to begin the oscillation you first stretch the string to the lowest point, once released from there it rises to the mean position(at which it has max velocity) A...from A it moves up to the extreme top which is B(velocity is 0). following that, it moves from B back to mean position(now labelled C) and then to the bottom most point which is D(where v is 0 again)
Got the motion?
So, lowest point is D

What no is the trapezium q?
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Offline sweetie

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Re: physics doubt
« Reply #12 on: April 29, 2010, 03:55:56 pm »
its Q22
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nid404

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Re: physics doubt
« Reply #13 on: April 29, 2010, 04:02:00 pm »
Q22) it can be called a triangle only upto 10 mm. Line's not straight after that.
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Offline sweetie

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Re: physics doubt
« Reply #14 on: April 29, 2010, 04:03:45 pm »
but its written in the Que's to treat the whole line as straight!!!
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