# Physics, Chemistry and Biology: Post your doubts here!

#### Gouki_Destruction

Hmm this is lyk the tenth time I get this question 2 day Zambia.
Ok , what is ur name ??

Ibrahim wbu

#### Getsuga juujisho

Salamu alaykum, why is it B?

#### ANAS_15_2002

View attachment 63656

Salamu alaykum, why is it B?
its kind of a common sense type of question it cant be D at all beacuse its exceeding the limit cant be C because it cant stay the same and cant be A because it cant go that low so its B, thats what i think

#### Getsuga juujisho

its kind of a common sense type of question it cant be D at all beacuse its exceeding the limit cant be C because it cant stay the same and cant be A because it cant go that low so its B, thats what i think

why is it D?

#### Ayesha Asif333

View attachment 63659

why is it D?
Because we are working with the same volume of that conducting putty, an increase in c.s.a will bring a decrease in the length by the same factor as the c.s.a ( Volume of cylinder=pie r square * length/height)

So hopefully u would be knowing that doubling the diameter would increase the c.s.a by 4 times {That if the diameter of 5 gives u an area of 25, then a diameter of 10 will give u an area value of 25*4}

the length will then decrease 4 times of the original value

So by the formula u can work out or otherwise that there will be an…

R=l/4 / 4A

R=l/4*1/4A

R=l/16A

… over all decrease in resistance by a factor of 16.

#### Dtrickster

Guys how was physics.... I almost cried when I saw how hard it was

#### studyingrobot457

Guys how was physics.... I almost cried when I saw how hard it was
which variant, I did p21 and p41, p21 was easy, p41 a bit tough, and had less time

#### Dtrickster

Adeen Atif does this question looks familiar to you? :'D
I think I did variant 1 .... How did u find that emf and what was the total resistance

Adeen Atif does this question looks familiar to you? :'D
omg I remember! we had a huge discussion over it and in the end it was concluded that...I did it completely wrong . ahh man I dont even understand it now

#### Ayesha Asif333

omg I remember! we had a huge discussion over it and in the end it was concluded that...I did it completely wrong . ahh man I dont even understand it now
Not to mention our moods that day

#### Moddy Study

I need help real quick.. ..

it's 0625_s10_qp_32 question number 9 section b (i)
why is the resistance 2 ohm but not 6/11??
shouldn't the circuit be a parallel ? please hellllp

#### Moddy Study

I need help real quick.. ..

it's 0625_s10_qp_32 question number 9 section b (i)
why is the resistance 2 ohm but not 6/11??
shouldn't the circuit be a parallel ? please hellllp

#### Hamnah Zahoor

I need help real quick.. ..

it's 0625_s10_qp_32 question number 9 section b (i)
why is the resistance 2 ohm but not 6/11??
shouldn't the circuit be a parallel ? please hellllp
I am guessing I am late but still...

And current favours the path where there is low resistance.

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#### Moddy Study

Thank You
but ...
doesn't the current split when there's a junction?

#### Hamnah Zahoor

Thank You
but ...
doesn't the current split when there's a junction?
Yes the current do split up when there is a junction but at points when on one of the paths the resistance is zero the current favours that path only.

#### PhysicsDoc

Physics Problem...
A uniform metal tube of length 5m and mass 9kg is suspended horizontally by two vertical wires attached at 50 cm and 150 cm respectively from the ends of the tube. Find the tension in each wire.
Hope you can help ^-^
Call the tensions in the two wires A and B newtons respectively. Take moments about one of the points where the wire is attached to the beam. If this is where the A force acts, then its moment will be zero and you can apply the principle of moments to find B. Once you have B you can simply use the fact that the total upward force is equal to the total downward force. In this case A + B = 9g newtons. Job done.