Physics: Post your doubts here!

[awesomaholic101]

What is the best book for A-Level Physics? Any book that covers the syllabus of 2016 completely?

http://issuu.com/cupeducation/docs/...and_a_le_a6c5aee47d8cf4/115?e=4655315/8019938
you can actually read the book an see if you like it

 

[Sarosh Jameel]

PLZ help me with june 2002 Q6 part (A) !!!

 

[Saad the Paki]

Can somebody explain how the answer is C? Constant spend means constant KE right?

 

[Saad the Paki]

see solution 786 at
http://physics-ref.blogspot.com/2015/05/physics-9702-doubts-help-page-158.html

Oops my bad !

 

[Sarosh Jameel]

PLZ help me with this !

 

[a_wiserME!!]

can someone pls explain this to me?? i got the first one because when S1 is open, no current flows... but i dont get the rest..
TIA

 

[robinhoodmustafa]

View attachment 57652


View attachment 57653

can someone pls explain this to me?? i got the first one because when S1 is open, no current flows... but i dont get the rest..
TIA

Just remember to use P=v^2/R or P=I^2/R when its asks for power dissipated.
also remember that every resistor are the same so they all have the value of 38.4 ohms
Resistor in Series are added while Resistor in parallel are inversed than added.
and also know that current prefers the least resistive path... such in case of ( Closed Closed Open).

Now try to solve it by yourself . If you cannot understand than feel free to contact.

 

[Sarosh Jameel]

PLZ help me to calculate absolute uncertainties for T^2 .. actually i have just started p5 ..

 

[hellen]

hellen here you go but don't depend on them as they are so much summarised!

Ty soooo much <<<<<3333

 

[Saad the Paki]

Please ! Some one help me solve this (Question 21) I have a test tomorrow

 

[robinhoodmustafa]

View attachment 57657 Please ! Some one help me solve this (Question 21) I have a test tomorrow

is the answer B?

 

[Liv2Stdy]

View attachment 57657 Please ! Some one help me solve this (Question 21) I have a test tomorrow

 

[Liv2Stdy]

PLZ help me to calculate absolute uncertainties for T^2 .. actually i have just started p5 .. View attachment 57656

I think its this equation,

 

[a_wiserME!!]

Just remember to use P=v^2/R or P=I^2/R when its asks for power dissipated.
also remember that every resistor are the same so they all have the value of 38.4 ohms
Resistor in Series are added while Resistor in parallel are inversed than added.
and also know that current prefers the least resistive path... such in case of ( Closed Closed Open).

Now try to solve it by yourself . If you cannot understand than feel free to contact.

yep i kinda got it.. thnx

 

[Sarosh Jameel]

I think its this equation,

View attachment 57659

Thanks a lot .. PLZ also help with this one to calculate uncertainty !

 

[Tozu Fofo]

Can anyone please give me good notes for Kinematics unit?
Thank in advance

 

[shayista547]

Can someone explain this to me please
''For the greatest efficiency the external resistance must be much greater than the internal resistance of the cell. However, for the maximum power to be delivered to the external circuit the internal resistance must be equal to the resistance of the external circuit, although the cell will only be 50% efficient.''
Why should the cell be 50% efficient but not fully efficient please?

 

[shayista547]

When strain is increased,it implies that length decreases according to strain=extension/length
when length decreases,resistance also decrease according resistance=resistivityXlength/area,right?
Then how come the answer is E?Maybe i can't understand the question itself.Help please!!
Thanks in advance

 

[Wolfgangs]

Can someone please give me the answer for this question?

 

[shayista547]

see solution 839 at
http://physics-ref.blogspot.com/2015/06/physics-9702-doubts-help-page-167.html

Thanks I totally understand it now