Physics: Post your doubts here!

[Sahil Gupta]

Answer is B,.
Explain with working someone plz

 

[Maayee]

http://onlineexamhelp.com/wp-content/uploads/2013/11/9702_w12_qp_13.pdf
can someone pls help me with question 33, the answer is D

 

[Mathemagical]

http://onlineexamhelp.com/wp-content/uploads/2013/11/9702_w12_qp_13.pdf
can someone pls help me with question 33, the answer is D

Area = π*R²
Area 1= π*0.5² =π*0.25
Area 2 = π*0.25² =π*0.0625

Area 1 = 4* Area 2

Since Volume is constant, L is 4 times.

Resistance is 4*4 times 0.2, which is 3.2.

 

[amal sharkawi]

CAN ANYONE ANSWER PLZ ????/??

 

[DESTROYER1198]

HELP PLZZZ is the extension of a spring inversely proportional to the diameter or the diameter squared

 

[Abdul Hanan]

These are the toughest physics MCQs for me.. please explain thanks.

just try them if you have not already

 

[69ermalik007]

help needed.....

 

[Mathemagical]

Elastic energy per unit volume = (½ Fx) / AL.
= Sx / 2L [F / A = S]
= S {strain} / 2
[Young modulus, E = stress S / strain. So, strain = S / E]

Elastic energy per unit volume = SS / 2E = S2 / 2E

 

[Mathemagical]

If the heating element is glowing light red, it's between 800 and 900 degrees.

 

[princess Anu]

 

[waqas123]

Try this one:

 

[nehaoscar]

How to do this one?

 

[The Sarcastic Retard]

View attachment 54599
How to do this one?

C ?

 

[nehaoscar]

C ?

Nope ... it's B

 

[nehaoscar]

How to do this one??

 

[Mahnoorfatima]

View attachment 54601
How to do this one??

It's a simple parallel and series circuit. Look the resistor with the junction is parallel to the three resistors with no junction between them. So, add 10+10+10 = 30 then solve for 30 and 10 as in a parallel circuit. Thus product/sum = 10x30/10+30 which is 7.5 which is B ie between 1 and 10 ohms.

 

[nehaoscar]

What are the correct estimated values for A,B and C?

 

[Abdul Hanan]

If the heating element is glowing light red, it's between 800 and 900 degrees.

Elastic energy per unit volume = (½ Fx) / AL.
= Sx / 2L [F / A = S]
= S {strain} / 2
[Young modulus, E = stress S / strain. So, strain = S / E]

Elastic energy per unit volume = SS / 2E = S2 / 2E

Thanks
any idea of the third one?

 

[nehaoscar]

Read the green writing first

 

[Abdul Hanan]

thanks