Physics MCQs thread.

[hassam]

 

[Zishi]

Because while its being earthed, and at the same time there's an electric filed between the plates, the charge won't move down the earth. It's a fact, learn it.

 

[hassam]

 

[hassam]

i never got it ryt

 

[Hateexams93]

Because while its being earthed, and at the same time there's an electric filed between the plates, the charge won't move down the earth. It's a fact, learn it.

and whats the answer ?

 

[hassam]

Because while its being earthed, and at the same time there's an electric filed between the plates, the charge won't move down the earth. It's a fact, learn it.

zisi this is wat ER says...bt i cnt undrstnd it
Too many candidates of all abilities gave the answer B. It is a very common misconception that an earthed
plate must have no charge on it. The presence of the negatively charged plate would make the potential of
the plate negative were there not some positive charge on it. Also, field lines to a negative charge must start
from a positive charge.

 

[Zishi]

The accuracy as provided in the question is 3%.

3% of the 327.66m/s is 9.83 which is a tenth figure!
So 326.66m/s to the nearest tenth would be 330m/s i.e 'C'.

 

[Zishi]

Because while its being earthed, and at the same time there's an electric filed between the plates, the charge won't move down the earth. It's a fact, learn it.

zisi this is wat ER says...bt i cnt undrstnd it
Too many candidates of all abilities gave the answer B. It is a very common misconception that an earthed
plate must have no charge on it. The presence of the negatively charged plate would make the potential of
the plate negative were there not some positive charge on it. Also, field lines to a negative charge must start
from a positive charge.

So you've to get your concept right about it. What I said is a fact(as ER says), so learn it. The explanation for it is far beyond scope of A-Level. :roll:

 

[hassam]

 

[xHazeMx]

i didnt manage to solve the question about the tank with the oil. what could be the answer and why ? ( page 14 )

 

[Zishi]

B

 

[Xenon]

Because while its being earthed, and at the same time there's an electric filed between the plates, the charge won't move down the earth. It's a fact, learn it.

zisi this is wat ER says...bt i cnt undrstnd it
Too many candidates of all abilities gave the answer B. It is a very common misconception that an earthed
plate must have no charge on it. The presence of the negatively charged plate would make the potential of
the plate negative were there not some positive charge on it. Also, field lines to a negative charge must start
from a positive charge.

So you've to get your concept right about it. What I said is a fact(as ER says), so learn it. The explanation for it is far beyond scope of A-Level. :roll:

You can think like this way, a plate connected to earth will have the same potential as earth. We know earth is given a potential of zero. thus the plate connected to earth will have zero potential and since the other plate is negatively charged, the lower plate is at a higher potential which can be thought as it being the positive plate. thus field lines move form the lower plate to the upper plate. I think B is incorrect as it shows field lines from a uncharged plate to a negatively charged plate which is not possible.

 

[hassam]

 

[hassam]

i dint completely undrstood that ans is 18.5

 

[Zishi]

i dint completely undrstood that ans is 18.5

Answer to which question is 18.5?

 

[xHazeMx]

i dint completely undrstood that ans is 18.5

i didnt use the cross-sectional area values which i really think it has something to do with the calculations

 

[xHazeMx]

i dint completely undrstood that ans is 18.5

Answer to which question is 18.5?

yes

 

[hassam]

 

[xHazeMx]

E ?

 

[hassam]

no thats wrong u zishi??