Physics: Post your doubts here!

[princess Anu]

I don't get whats wrong in B &D?

 

[nehaoscar]

Can someone please give me the values for the wavelengths and frequencies of all the electromagnetic radiations please???

 

[DaniyalK]

Why not B?

You are subtracting 2 readings so the error is (1/60) * 100

 

[princess Anu]

Why not B?

is it D?
The uncertainty in temp rise is O.5*2 because Rise = final -initial temp.. so the uncertainty in both the temp is added to give a final uncertainty of 1.

 

[Xtreamer]

is it D?
The uncertainty in temp rise is O.5*2 because Rise = final -initial temp.. so the uncertainty in both the temp is added to give a final uncertainty of 1.

yes i think so

 

[princess Anu]

Can u help me with this.? why is B wrong

yes i think so

 

[awesomaholic101]

Why not B?

(0.5*2/60)*100 = 1.7%

 

[Xtreamer]

Can someone please give me the values for the wavelengths and frequencies of all the electromagnetic radiations please???

Just remember the wavelengths then work out the frequencies by v=f(lambda) where v = 3 * 10 power 8 ( value is given in data booklet)
The wavelengths

Gamma 1o power -14 to -10
X rays power -13 to -8
UV power -8 to -7
Visible power -7
Micro power -7 to -3
Radio power -1 to 6

 

[BhaiArshad]

 

[princess Anu]

Why is C incorrect? external forces cancelling out means 0 resultant force right ??

 

[Ahmed Aqdam]

At X it is at height 5 m as 1/0.2=5
At Y height will be 5.3 m so GPE will be 5.3*0.2=1.06 J

 

[Ahmed Aqdam]

Why is C incorrect? external forces cancelling out means 0 resultant force rightView attachment 54946 ??

There could be a change in mass.

 

[Xtreamer]

Can u help me with this.? why is B wrong

What is the Answer is it D?

 

[BhaiArshad]

is it D?
The uncertainty in temp rise is O.5*2 because Rise = final -initial temp.. so the uncertainty in both the temp is added to give a final uncertainty of 1.

Yes but it is like this. Rise = Final - 40.
Why is 40 counted in this?

 

[Xtreamer]

– Ans: C. gravitational PE = 1 + (0.2x0.3) = 1.06J

Source: http://physics-ref.blogspot.com/2014/10/9702-june-2014-paper-12-worked.html

 

[Abdul Hanan]

how?

 

[Aly Emran]

Guys how to do these type of qstns? Plzz explain
Thanks in advance

 

[princess Anu]

No

What is the Answer is it D?

A

 

[Ahmed Aqdam]

View attachment 54947
how?

F=qE so E=F/q
Now according to work done formula F=K/d.
Hence K/dq.

 

[princess Anu]

Yes but it is like this. Rise = Final - 40.
Why is 40 counted in this?

Counted in what?

There could be a change in mass.

so? :S