Edexcel Physics Unit 2 "Physics at work" June 2013

Competition - post a photo you've taken of nature >>

Scroll to see replies

Hi guys Did anyone get the same answer as me for the 4.3ev resonant frequency question? I did......... E=hf. 4.3x 1.6 x10^-19=6.63x10^-34f so when rearranging this, f=1 x10^15

I got that!

Reply 741

ALevel96

MCQ answers:

Let me know if you disagree.

1)D
2)D
3)D
4)B (as said by others)
5) no question
6)C
7)B
8)A
9)A
10)A

Reply 742

x0x

Original post by ALevel96

MCQ answers:

Let me know if you disagree.

1)D
2)D
3)D
4)B (as said by others)
5) no question
6)C
7)B
8)A
9)A
10)A

is question 7 about the wire with length l and the answers were in terms of drift velocity?
i remember getting v/2 .. i think it was B ?

Reply 743

ALevel96

7 is the radiation flux question

Reply 744

x0x

Original post by ALevel96

7 is the radiation flux question

Do you have the list of questions and their answers? if so then i'd greatly appreciate it if you post the list?

Reply 745

krisshP

Original post by Alexsk

Guys isn't 57-60 very high for an A? The answer was V/2, and has nothing to do with charge carriers. Also, can somebody give a definition to critical angle? For the question about wavelength I did not write about troughs or peaks and just said its the distance travelled by a wave for a complete oscillation to take place. Is that correct?

Critical angle is the angle of incidence at which angle of refraction=90*, so light travels along medium boundary.

Reply 746

B-Stacks

Original post by x0x

Do you have the list of questions and their answers? if so then i'd greatly appreciate it if you post the list?

Someone kindly posted them here. https://www.dropbox.com/sh/v6ydqbfrg20whtb/ZWR-r9ZOSH?lst#/
As for the answers I guess we just work them out ourselves

Reply 747

krisshP

Original post by x0x

Do you have the list of questions and their answers? if so then i'd greatly appreciate it if you post the list?

https://www.dropbox.com/sh/v6ydqbfrg20whtb/ZWR-r9ZOSH?lst

Another user posted ^

Reply 748

Jaydude

Original post by hamzeh h

im thinking 58-59

Way too high. 54 or 56 max.

Posted from TSR Mobile

Reply 749

Jaydude

Original post by ALevel96

MCQ answers:

Let me know if you disagree.

1)D
2)D
3)D
4)B (as said by others)
5) no question
6)C
7)B
8)A
9)A
10)A

I disagree with 10, I got D. But either could be correct. Your thoughts?

Posted from TSR Mobile

Reply 750

B-Stacks

For question 4 wouldn't it be 2v?
Because v=I/nq2A because the area is doubled. Bring the 2 over and be 2v? Or am I completely wrong?

Reply 751

x0x

Original post by x0x

is question 7 about the wire with length l and the answers were in terms of drift velocity?
i remember getting v/2 .. i think it was B ?

Yes! all of my MC answers match yours :biggrin:

i forgot what question 5 was :P

Reply 752

Alexsk

I wrote that 3 is C. Is that wrong?

Reply 753

x0x

Original post by B-Stacks

For question 4 wouldn't it be 2v?
Because v=I/nq2A because the area is doubled. Bring the 2 over and be 2v? Or am I completely wrong?

You need to consider two equations here
Resistivity and the drift velocity equation
from the resistivity one you can tell that nothing changes as l and A are both doubled so they cancel out. That means that I is constant as R is unchanged
then you use I=nAvq . A is doubled but there is no l so it has to be v/2
I don't think i explained it well at all but i think v/2 is the answer. If anyone can explain this better please do so :smile:

Reply 754

B-Stacks

Original post by Alexsk

I wrote that 3 is C. Is that wrong?

If you look at where the waves finish you will see that Y is ahead of X.

Reply 755

ALevel96

Original post by Jaydude

I disagree with 10, I got D. But either could be correct. Your thoughts?

Posted from TSR Mobile

Superposition produces an interference pattern

Reply 756

ALevel96

5 was the Doppler question and I think I chose C

Reply 757

x0x

Original post by ALevel96

5 was the Doppler question and I think I chose C

so S was moving towards O and O was moving towards s?
is that choice C? i that is the one i have chosen

Reply 758

ambbs

Original post by Alexsk

I wrote that 3 is C. Is that wrong?

I put C too. I think we're right, because I remembered seeing this in the textbook ImageUploadedByStudent Room1370514521.634454.jpg

ImageUploadedByStudent Room1370514527.631827.jpg

Posted from TSR Mobile

Reply 759

vinhvu95

Did anyone see through the trick question in question 17? It wasn't a negative gradient graph, because that's when the voltmeter is measuring the load resistance, but in this question the voltmeter was measuring the Pd at the battery, so it would've been a positive graph

Posted from TSR Mobile