Physics, Chemistry and Biology: Post your doubts here!

[Mustafa84922]

Are there any important definitions we are supposed to know??
There are soo many so! ?

hey do you have any doubt in physics pls ask im bored and there is nothing much left for me to do
thought i might be useful for others xD

 

[Saad the Paki]

hey do you have any doubt in physics pls ask im bored and there is nothing much left for me to do
thought i might be useful for others xD

Can u tell me the difference between e.m.f and p.d?

 

[Mr.Physics]

Can u tell me the difference between e.m.f and p.d?

E.m.f is the force that drives the electrons in the circuit. It comes from the battery. While pd is the difference between the two points in the circuit or the two battery terminals.

 

[Mustafa84922]

Can u tell me the difference between e.m.f and p.d?

Emf is the work done by any electrical source, to drive a one unit charge around a circuit
Emf is a force that transfers the current throughout the circuit, and even transmits it inside the cell. It remains constant
Potential difference, however, is the the amount of potential energy per unit of charge between two points. It is varies throughout the circuit

 

[Mustafa84922]

Can u tell me the difference between e.m.f and p.d?

one more thing emf is the cause and potential difference is the result, in other words potential difference is caused due to an emf.......

 

[sfhn_128]

one more thing emf is the cause and potential difference is the result, in other words potential difference is caused due to an emf.......

can u solve ques o/n 08 31 ques 2(a) and (b)...........thanks in advance!

 

[Mustafa84922]

can u solve ques o/n 08 31 ques 2(a) and (b)...........thanks in advance!

sure just stay online ill take afew minutes

 

[sfhn_128]

sure just stay online ill take afew minutes

thanks!!!!

 

[Mustafa84922]

can u solve ques o/n 08 31 ques 2(a) and (b)...........thanks in advance!

2(a) is just basic stuff
we have to choose two masses so that their ratio may be 12:8(3:2) 8:4(2:1) or 12:4(3:1) this is because we only have 3 holes on either side at fixed distances
take whatever ratio you like, in this case 3:2
take a mass ill take 600g as it is the highest i have to place this in resprect to 3
so 600*2/3 =400 the other mass i need to take is 400
600g is to be placed at second dot on either side and the 400g is to be placed at the third dot on the side opposite to 600g

pls wait till i solve (B)

 

[Mustafa84922]

Part (b) when we hang both the masses we will check wether the disc rotates or not if the disc remains in its position and does not rotate to either side then the net moment is zero........
You are welcome to ask any other question

 

[Mustafa84922]

thanks!!!!

btw what about the other parts can you solve them???

 

[sfhn_128]

Part (b) when we hang both the masses we will check wether the disc rotates or not if the disc remains in its position and does not rotate to either side then the net moment is zero........
You are welcome to ask any other question

Thanks alot.......Giving p3 and p1 tomorrow?

 

[sfhn_128]

btw what about the other parts can you solve them???

Can u explain them too?!

 

[Mustafa84922]

Thanks alot.......Giving p3 and p1 tomorrow?

yea I hope they'll be easy
I wish all of us may get A* InshaAllah

 

[Mustafa84922]

Can u explain them too?!

YEa sure

 

[sfhn_128]

yea I hope they'll be easy
I wish all of us may get A* InshaAllah

InshaAllah! Best of Luck!

 

[Mustafa84922]

Can u explain them too?!

PART(C)
look the first mass i chose was 600 and i placed it at the second dot which means 8 cm from the pivot
so, 600*8 = 4800
the second one was 400 and it was placed at third dot therefore, 400*12= 4800
1 marks is for both the moments and one is for the fact that they are equal

 

[Mustafa84922]

InshaAllah! Best of Luck!

Thank you and wait for the last part pls

 

[Mustafa84922]

InshaAllah! Best of Luck!

here you go.....
PART(D)
the two masses we chose were 600g and 400g, both of them are acting downwards
first we convert these to newtons, but for that they must be in kg so 600g=0.6kg and 400g=0.4kg
we multiply both by 10 to get their weights (forces) 0.6kg=6N and 0.4kg=4N, so until now we have a total of 10N force acting downwards but we know that the disc also has a mass which is 200g=0.2kg=2N, therefore now the downward forces are equal to 12N,
Thus we know that 12N is the force acting on the pivot

 

[Mustafa84922]

InshaAllah! Best of Luck!

there is no need to mention anything about upward forces = downward forces because the asked about force acting ON the pivot not force EXERTED by the pivot