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AQA Physics A Unit 1 New Spec RESIT

Haruhi

Its about the resit paper on 21st May 2009

Omg How Did You Find It?

It Was Go0o0o0o0o0o0o0od! :biggrin:

Reply 1

MGIL

this was in january right?
blimey youre late

Reply 2

Haruhi

OP

My answers:

1. An isotope is an element with the same number of protons but different number of neutrons

2. Protons in table: 92
Unit of Specific charge CKg-1
S.C = 3x10^7
Neutrons = 146 or 145

Q about ground state = blalah about excitation and dexcitation of electrons.

Sigma has 3 quarks, 1 of them is strange.

Charge and baryon number are conserved

strangeness is not conserved

its a strong interaction

Neutrons decay into protons

circuit must have cell, diode, variable resistor, ammeter and a voltmeter in parallel with the diode.

blala about how to use the circuit to get the results in a graph.

Current = 12/8 = 1.5

Current for 4 ohm resistor = 2.6?

frequency for wave = 98.8 Hz

1.5 x 2 divisions = 3V

Vrms = 3 / square root of 2

Thats all I can remember at the moment =/ Sorry my memory fails me.

Reply 3

Haruhi

OP

MGIL

this was in january right?
blimey youre late

Sorry, I am talking about the resit done today :smile:

Reply 4

Near

10

That resit was solid. =_= When did I ever learn about Sigma? and the 6 mark questions were just crap. There was 3 of them and I only answered 1. The person who wrote this paper should go and die in some dark alley.

Reply 5

Haruhi

OP

Near

That resit was solid. =_= When did I ever learn about Sigma? and the 6 mark questions were just crap. There was 3 of them and I only answered 1. The person who wrote this paper should go and die in some dark alley.

LOL Sigma is a baryon and all baryons have 3 quarks.

Since its strangeness is -1 then it has 1 strange quark.

for the sigma equation you just had to prove that the charge and baryon numbers are qual on both sides.

and for the last 2 questions, strangness is not conserved in a strong interaction. Its always conserved in the weak interaction.

Oh and I forgot... Neutron decays into a proton :biggrin:

Reply 6

MGIL

oh, sorry. :smile:

My friend got a C in January but decided not to retake and concentrate on unit 1-however it seems my school wouldn't have let her anyway as they consider it a pass.

Reply 7

ssj786

what was the answer to 'I/V diode' question that was worth 6 marks!

Reply 8

*Mathematician*

Haruhi

My answers:

1. An isotope is an element with the same number of protons but different number of neutrons

2. Protons in table: 92
Unit of Specific charge CKg-1
S.C = 3x10^7
Neutrons = 146 or 145

Q about ground state = blalah about excitation and dexcitation of electrons.

Sigma has 3 quarks, 1 of them is strange.

Charge and baryon number are conserved

strangeness is not conserved

its a strong interaction

Neutrons decay into protons

circuit must have cell, diode, variable resistor, ammeter and a voltmeter in parallel with the diode.

blala about how to use the circuit to get the results in a graph.

Current = 12/8 = 1.5

Current for 4 ohm resistor = 2.6?

frequency for wave = 98.8 Hz

1.5 x 2 divisions = 3V

Vrms = 3 / square root of 2

Thats all I can remember at the moment =/ Sorry my memory fails me.

Your answers are pretty similar to mine but I had weak interaction (if it was strong then strangeness would be conserved).

My specific charge answer was 6.2x10^7.

I didn't read circuit man! I drew the damn graph... :shifty:

For the electricity ones, because they were in parallel, they have the same voltage so the p.d across each one is 6.

Therefore V = IR, 6 = 8I, I=0.75

And for the second part 6-0.65 = 4I

... :smile:

The rest are pretty similar... :yep:

Reply 9

Chunkeymonkey62

2

I got 283 as my neutrons! Didnt minus 92! :frown:

I put lepton and charge are conserved as the sigma might have been a antiparticle. Would I still get the mark?

Reply 10

*Mathematician*

Chunkeymonkey62

I got 283 as my neutrons! Didnt minus 92! :frown:

I put lepton and charge are conserved as the sigma might have been a antiparticle. Would I still get the mark?

Lepton and charge was fine.

I had 146 as my neutrons (I think this is correct because the two isotopes of Uranium are 235 and 238)

What was the random validated question?

Reply 11

Chunkeymonkey62

2

Explain what Validated Evidence is. I think it was another of those rubbish questions, like they have in the january past paper!

Reply 12

*Mathematician*

Chunkeymonkey62

Explain what Validated Evidence is. I think it was another of those rubbish questions, like they have in the january past paper!

You won't beat the good old why do scientists need to test their theories... :eek3:

What has happened to physics?... :shifty:

The good old days where students spent 37 minutes on question one which took 6 pages of working and you had to quote all 3 of Newton's laws and prove Einstein's law 7 times... :p:

Reply 13

Jeester

14

Oh Em Gee!
Like just got out!
Such an AMAZING exam!
So much better than last time!
So glad I retook!

Reply 14

Tomato_Soup1992

14

Heres the questions for anyone who cant remember

Q1
a) What is an isotope?
bi) How many protons in the 2nd atom? 92
ii)What is the charge/mass ratio of isotope 1? 37.5MC/kg
iii)How many neutrons in 2nd atom? 146

Q2
a)Explain excitation......
b)Why are the kinetic energies of the electrons different?
ii) Calculate 9eV in joules 1.44x10^-18
iii) What is the frequency of the emmited photons? 1.93x10^15

Q3
a)i) How many quarks in the sigma +? 3
ii)How many of these are strange? 1
bi) Whats conserved? Charge and Baryon number
ii) whats not conserved? Strangeness
iii)Type of interaction? weak
iv) What will the neutron decay in to? Proton

Q4
ai) Effect of increased frequency on photoelectrons? greater Kinetic energy
ii) Effect of increased intensity? Nothing
b) Explain the meaning of validated evidence

Q5
a)Draw circuit to calculate I-V curve for diode
b) Explain how to obtain curve
ci) current through 8 ohm resistor? 1.5A
ii) current through 4 ohm resistor? 2.84A

Q6
a) Calculate frequency of AC source 98.8HZ
b)Calculate peak pd 3v
c) Calculate RMS Pd 2.12v
d)Explain the trace of the oscilloscope when the time base is switched off

Q7
a) Calculate terminal Pd
b) Calculate Resistivity

Reply 15

Chunkeymonkey62

2

Was the last question a trick one?

They gave you I, r and E! Also, the resistivty was straight forward. Seems too easy.

Also, what you guys put for Freq/Intense

Frequency gives it more enery, Intensity increase the number of electrons

Reply 16

Jeester

14

My specific charge answer was 6.2x10^7.

For the electricity ones, because they were in parallel, they have the same voltage so the p.d across each one is 6.

I got 3.76 as my specific charge...
I got current to be 0.16 for the 4 ohm resister I think.

Haruhi

frequency for wave = 98.8 Hz

And I got 0.75hz... :confused:

Reply 17

Tomato_Soup1992

14

*Mathematician*

Your answers are pretty similar to mine but I had weak interaction (if it was strong then strangeness would be conserved).

My specific charge answer was 6.2x10^7.

I didn't read circuit man! I drew the damn graph... :shifty:

For the electricity ones, because they were in parallel, they have the same voltage so the p.d across each one is 6.

Therefore V = IR, 6 = 8I, I=0.75

And for the second part 6-0.65 = 4I

... :smile:

The rest are pretty similar... :yep:

pd is 12 across the parallel combo so its 12/8

Reply 18

ben20012004

guys with the frequency of the AC source did people measure one wave to be 6.8 dv or a.5 waves to be 15 dv. DIAGRAM NOT DRAWN PROPORTIONALLY, btw the guy above increasing intensity increases number of emmitted photons x