Physics, Chemistry and Biology: Post your doubts here!

Messages
933
Reaction score
2,276
Points
253
thanks but nvm about that. what about THIS QUESTION?
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.
 
Messages
5
Reaction score
2
Points
13
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
 
Messages
5
Reaction score
2
Points
13
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
 
Messages
426
Reaction score
373
Points
73
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...
Untitled.png

And current favours the path where there is low resistance.
 
Last edited:
Messages
2
Reaction score
1
Points
3
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.
 
Top