Physics, Chemistry and Biology: Post your doubts here!

[Hanzalla]

ALSO can u explain why the answer is A not C
View attachment 62109

ITs A using the Parallelogram Method, ALSO You can see the direction of both the forces thus resultant force will be in the same direction.

 

[Ayesha Asif333]

View attachment 62101 View attachment 62102 1st pic is from 2005 oct/Nov and the other is from 2006 may/June all varient 2

for the first one you can write - that stick the protractor to the bench while placing its centre point at the point where the scale touches the bench
for the second ques - its simple one mark...write , use a set square it is more stable therefore easier to use ...measure the vertical height from the bench till the meter rule to see it the ruler is horizontal

also, these yrs don't have variants

 

[Adeen Atif]

Guys i need help in physics whats the hardest paper u have ever done it would be better if they are from 2016
and any important tips especially for paper 6 because i am suffering in tht paper
thanks!

I'm in the same boat as you
But as far as I've noticed Paper 62 2016Oct/Nov was the hardest of all Paper 6s.
You just need to revise and revise and the most important tip is to NOT open any past paper unless you, ve revised the full syllabus.
I hope I was helpful,Good Luck!

 

[Adeen Atif]

Guys! Ive a question.
How does increasing the voltage decrease the heating effect of current?

 

[Shahid Karim]

Guys! Ive a question.
How does increasing the voltage decrease the heating effect of current?

Current is responsible for the heating effect.
As the resistance increases, Voltage increases, current decreases (which means less heating effect)
You can increase the voltage and decrease the current by Step up transformer.

 

[Shahid Karim]

Does a variable resistor, thermistor and LDR follow Ohm's law?

 

[Adeen Atif]

Does a variable resistor, thermistor and LDR follow Ohm's law?

Thermistor and LDR don't follow Ohm,s Law ,since their resistance depends on temperature and light.
However Variable resistor,s resistance doesn't,t depend on any factor (unless its overheated),So it does obey the Ohm,s Law

 

[Adeen Atif]

Current is responsible for the heating effect.
As the resistance increases, Voltage increases, current decreases (which means less heating effect)
You can increase the voltage and decrease the current by Step up transformer.

But isn't Voltage directly proportional to Current?

 

[Ayesha Asif333]

Inversely proportional

But ohm's law states that the electrical current (I) flowing in an circuit is proportional to the voltage (V) and inversely proportional to the resistance (R). therefore, if the voltage is increased, the current will increase provided the resistance of the circuit does not change.

 

[Adeen Atif]

But ohm's law states that the electrical current (I) flowing in an circuit is proportional to the voltage (V) and inversely proportional to the resistance (R). therefore, if the voltage is increased, the current will increase provided the resistance of the circuit does not change.

Actually this all (ohm,s law thing) isnt really applicable in original experiments.But you can say that if voltage will be increased the current passing through a resistor would also increase which could result in more resistance since more electons are now present inside the resistor making it difficult for them to pass through and will result in current being decreased.The resistor then heats up since the electrons are applying quite a lot of energy on the walls of the resistor.And inturn the voltage (aka P.D) will increase since more energy is spent by electrons while passing through.
P.s Eventhough all what I wrote above may seem incomprehensible at the first time,If read twice you will understand it
Additional P.s Good Luck for tomorrow!

 

[Adeen Atif]

Actually this all (ohm,s law thing) isn't really applicable in original experiments.But you can say that if voltage will be increased the current passing through a resistor would also increase which could result in more resistance since more electrons are now present inside the resistor making it difficult for them to pass through and will result in current being decreased.The resistor then heats up since the electrons are applying quite a lot of energy on the walls of the resistor.And in turn the voltage (aka P.D) will increase since more energy is spent by electrons while passing through.
P.s Even though all what I wrote above may seem incomprehensible at the first time , If read twice you will be able to understand it.
Additional P.s Good Luck for tomorrow!

 

[Adeen Atif]

URGENT!
Guys! Can you plzz solve the part d of question 2 in the link below.Plzzz
http://dynamicpapers.com/wp-content/uploads/2015/09/0625_s16_qp_62.pdf

 

[Hanzalla]

But ohm's law states that the electrical current (I) flowing in an circuit is proportional to the voltage (V) and inversely proportional to the resistance (R). therefore, if the voltage is increased, the current will increase provided the resistance of the circuit does not change.

Sorry I forgot yes according to Ohms law it is directly proportional

 

[Ayesha Asif333]

Additional P.s Good Luck for tomorrow!

Thnx! GL to you too and i need special prayers for today

 

[Ayesha Asif333]

URGENT!
Guys! Can you plzz solve the part d of question 2 in the link below.Plzzz
http://dynamicpapers.com/wp-content/uploads/2015/09/0625_s16_qp_62.pdf

since the cube is larger than the width of the metre rule, to make sure we put the cube on exactly the point on scale we want and on its centre of mass , we measure the width of the cube, divide the width by 2 , mark the middle position on the cube and then put that marked position directly above the point on ruler

 

[Ayesha Asif333]

Actually this all (ohm,s law thing) isnt really applicable in original experiments.But you can say that if voltage will be increased the current passing through a resistor would also increase which could result in more resistance since more electons are now present inside the resistor making it difficult for them to pass through and will result in current being decreased.The resistor then heats up since the electrons are applying quite a lot of energy on the walls of the resistor.And inturn the voltage (aka P.D) will increase since more energy is spent by electrons while passing through.
P.s Eventhough all what I wrote above may seem incomprehensible at the first time,If read twice you will understand it

i am confused!

 

[Ayesha Asif333]

Sorry I forgot yes according to Ohms law it is directly proportional

happens...

 

[Adeen Atif]

since the cube is larger than the width of the metre rule, to make sure we put the cube on exactly the point on scale we want and on its centre of mass , we measure the width of the cube, divide the width by 2 , mark the middle position on the cube and then put that marked position directly above the point on ruler

Thankyou!

 

[Adeen Atif]

i am confused!

Thnx! GL to you too and i need special prayers for today

No prob,Inshallah we all will ace the exam!

 

[Ayesha Asif333]

No prob,Inshallah we all will ace the exam!

Alhamdulillah, it's done now...
P2 was great but p6 was lil hard