ATAR Notes: Forum

Archived Discussion => 2010 => End-of-year exams => Exam Discussion => Victoria => Physics => Topic started by: Munkea on November 10, 2010, 01:43:04 pm

Title: MULTIPLE CHOICE ANSWERS - SOUND
Post by: Munkea on November 10, 2010, 01:43:04 pm
Just posting up my suggested answers. May be a few discrepancies, however I'm pretty confident with these.
 
1. B
2. D
3. A
4. C
5. C
6. D
7. C
8. C
9. B
10. A
11. A
12. D
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: Whatlol on November 10, 2010, 01:48:33 pm
Here are my MCQ answers for sound
1 - B
2- D
3 -A
4 -C
5- C
6 D
7 C
8 C
9 B
10 B
11 A
12 D
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: Sheen on November 10, 2010, 01:49:35 pm
B
D
A
C
C
D
C
C
B
B
A
D
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: curious111 on November 10, 2010, 01:50:13 pm
Was the microphone one just the linear region (I think it was 200-2000)?
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: Whatlol on November 10, 2010, 01:50:18 pm
lookin good everyone
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: Whatlol on November 10, 2010, 01:50:34 pm
Was the microphone one just the linear region (I think it was 200-2000)?

thats what i put down
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: Sheen on November 10, 2010, 01:51:21 pm
Here are my MCQ answers for sound

hi5~~~~~
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: xZero on November 10, 2010, 01:52:20 pm
Fk I got 1.c ... There goes a mark
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: matty.k on November 10, 2010, 01:54:46 pm
wasn't the first sound intensity question A, i just subbed in A into the sound intensity formula and it gave me 70db so i went with A??
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: byr0003 on November 10, 2010, 01:57:56 pm
yeah its A for the sound intensity one... question 3!
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: John President on November 10, 2010, 02:01:10 pm
Here are my MCQ answers for sound
1 - B
2- D
3 -A
4 -C
5- C
6 D
7 C
8 C
9 B
10 B
11 A
12 D
Same here. A lot of my friends at A for question 10.
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: Xavier1234 on November 10, 2010, 02:11:17 pm
Here are my MCQ answers for sound
1 - B
2- D
3 -A
4 -C
5- C
6 D
7 C
8 C
9 B
10 B
11 A
12 D
Same here. A lot of my friends at A for question 10.

yeah i put down A as well coz i was looking at the phon line at the back page, and increase hz to 3000 increases the dB, so i thought it the graph should be decreased since it should be same intensity. lol im not sure. could be wrong. it was defs A or B.
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: rubiks on November 10, 2010, 02:16:01 pm
I put down A aswell because I didn't realise it was part of question 9. I just assumed same intensity=same amplitude. My teacher said it was B
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: qshyrn on November 10, 2010, 02:17:07 pm
Just posting up my suggested answers. May be a few discrepancies, however I'm pretty confident with these.
 
1. B
2. D
3. A
4. C
5. C
6. D
7. C
8. C
9. B
10. A
11. A
12. D
does anyone remember q7? i got B for that
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: supernatural on November 10, 2010, 02:19:19 pm
Fk I got 1.c ... There goes a mark

each detailed study question is worth 2 marks
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: mahcann on November 10, 2010, 02:24:55 pm
B D A C C D C C B A A D
LOOKING GOOD
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: jpcauchi on November 10, 2010, 02:33:45 pm
1. B     330/512
2. D    Oscillates horizontally
3. A    10^7*10^-12=10^-5
4. C    4 times the radius, therefore 16th the intensity, 12 dB change, 58 dB
5. C    50 phon
6. D     330/(4*133)
7. C    3* previous answer
8. C    320/(2*L)
9. B    200-2000Hz is where the graph is flat - fidelity
10.B    The period shortens and the amplitude increases because the microphone is more sensitive to 3kHz than 1kHz
11. A   Baffleboad prevents out of phase waves from front and back interfering
12. D   The tweeter behind the tv cant diffract around the tv
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: gamblor0 on November 10, 2010, 02:35:18 pm
Q 10 was A.
it said it has the same sound or something along those lines so the amplitude was the same
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: SixWinged on November 10, 2010, 02:35:29 pm
I seem to be getting the same as you guys :)

That Q10 was a tricky one considering it didn't seem like it continued on from Q9, had to be paying attention.
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: kyzoo on November 10, 2010, 02:36:39 pm
Got the exact same answers as OP
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: coletrain on November 10, 2010, 02:38:53 pm
so was q 10 a continuation of q9 or not? i dont remember
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: kyzoo on November 10, 2010, 02:42:40 pm
1. B     330/512
2. D    Oscillates horizontally
3. A    10^7*10^-12=10^-5
4. C    4 times the radius, therefore 16th the intensity, 12 dB change, 58 dB
5. C    50 phon
6. D     330/(4*133)
7. C    3* previous answer
8. C    320/(2*L)
9. B    200-2000Hz is where the graph is flat - fidelity
10.B    The period shortens and the amplitude increases because the microphone is more sensitive to 3kHz than 1kHz
11. A   Baffleboad prevents out of phase waves from front and back interfering
12. D   The tweeter behind the tv cant diffract around the tv


for 10, why does the amplitude increase? I'm 100% sure it said that the two soudns were of the same intensity level.
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: SixWinged on November 10, 2010, 02:42:47 pm
so was q 10 a continuation of q9 or not? i dont remember

Yeah, it was the same microphone. hence for the same sound intensity reaching the microphone, it would record a higher/lower value depending on frequency.
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: m@tty on November 10, 2010, 02:43:27 pm
10 is A, not B.

kyzoo is right. It said that the intensity was made to be EXACTLY the same after the frequency was changed.
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: kyzoo on November 10, 2010, 02:43:43 pm
so was q 10 a continuation of q9 or not? i dont remember

Yeah, it was the same microphone. hence for the same sound intensity reaching the microphone, it would record a higher/lower value depending on frequency.

but that's perceived loudness =/ I thought asme intensity produce same sound level regardless of how we hear it, and regardless of frequency
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: SixWinged on November 10, 2010, 02:44:52 pm
so was q 10 a continuation of q9 or not? i dont remember

Yeah, it was the same microphone. hence for the same sound intensity reaching the microphone, it would record a higher/lower value depending on frequency.

but that's perceived loudness =/ I thought asme intensity produce same sound level regardless of how we hear it, and regardless of frequency

Perceived loudness is the phon graphs with hearing. I can't remember the exact question, but it was asking for the value that the microphone obtains (for want of a better word). The microphone obtains a higher value for frequencies it is more sensitive to.
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: kyzoo on November 10, 2010, 02:46:28 pm
hmmm haha interesting dispute
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: jpcauchi on November 10, 2010, 02:50:57 pm
LOL true, interesting dispute

I wrote A first, then changed it when i realised that Q10 followed on from Q9

It said that the sound intensity was exactly the same when it reached the microphone
And the question said what would be read on the oscilloscope

And cos the y axis was in arbitrary units, the amplitude would be much higher. Cos at 1khz, the graph on the page prior had the output of the microphone at 0dB and at 3khz as +6dB.

So i figure the oscilloscope would have a higher output when its 3khz as opposed 1khz, even though the intensity was the same.

Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: garliczombie on November 10, 2010, 02:52:01 pm
it was intensity level not phon though. so it should be A because it says the intensity level stays the same.
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: John President on November 10, 2010, 02:55:17 pm
The microphone is not of equal fidelity at 1000 and 3000 Hz though, so on the CRO display the 3000 Hz sound will have greater amplitude I believe...so B.
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: jpcauchi on November 10, 2010, 02:55:34 pm
Phon has nothing to do with this question.

Intensity is measured in Wm^-2

So at the microphone, the intensity is the same.
And the reading on the oscilliscope which is attached to the microphone would vary with the frequency because the microphone is more sensitive to 3kHz than it is to 1kHz


Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: meefz on November 10, 2010, 02:59:58 pm
hold up isnt fidelity when the graph is higher above 0??
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: Munkea on November 10, 2010, 05:30:04 pm
I said A for question 10 as the question stated that the intensity levels had to stay the same. Just seemed like the logical answer.
Title: Re: MULTIPLE CHOICE ANSWERS - SOUND
Post by: jackchan1993 on November 10, 2010, 05:32:12 pm
i think it should be B, it said they were the same intensity, but u had to refer the the graph, and the microphone was more sensitive to the higher frequency sound, so its amplitude had to be higher than the other sound.