Physics P2 Unofficial Markscheme Edexcel.

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Question 3 (c) about hospital staff, I don't know if what I put was right, but I said: "Beta particles and gamma rays can mutate DNA causing cancer."

Gamma rays are highly penetrative so can cause permanent damage/mutations to cells from outside the body when exposed to a large dose. Large dose of gamma on outside is similar to small dose of alpha inside the body(which is very harmful)

(edited 7 years ago)

Reply 101

Dylanuk16

For the question about how hospital staff take precautions i put standing behind a glass window. Will i still get mark?

Reply 102

dina.yasmin

Original post by Penguin_S

What did you guys tick for the question on current and voltage I ticked decrease decrease so c

Posted from TSR Mobile

I ticked D but I don't think it was correct

Reply 103

fluctuation_0

Q1. Static Electricity

a. What is the diagram pointing to? (1)
Answer - Proton.
b. Why does the girl get positively charged as she walks across the nylon carpet? (3)
Answer - The insulating soles of the girl’s shoes rub against the nylon carpet (1)
Electrons are transferred (1)
From the girl to the carpet (1)
c. Why does she get a small electric shock when she touches the metal handle of the door? (2)
Answer - Metal is a conductor (1)
Charge flows (from girl) to the conductor (1)
For an easy route to the ground (1)
d. Math question.
Answer - 6.3C (0.07A * 90)

Q2. Nuclear Fission & Fusion.
a. What is the difference between a fission and fusion reaction?
b. Fill in the blanks (number of protons and neutrons)
Protons - 92
Neutrons - 143
c.
d. Graph question about correlating temperature and fusion reactions per second.
Fusion needs a high temperature to overcome repulsion between positive nuclei. The graph shows a correlation between the increase in rate of fusion reaction per second and temperature - as temperature increases, so does rate of reaction. (thank you to L0st45!)

Q3. Half Life (I think)
a. Half life of Iodine-131.
Answer- 8 days.
b. Estimate half life of Iodine-131 8 days ago.
c. Why do hospital staff have increased risks from handling Iodine-131?
Answer- Beta and gamma are ionising radiation (1)
If they enter the body, they could collide with (molecules of) genetic material / DNA (1)
This could cause cell mutations (1)
Which may lead to tissue damage / cancer (1)
d. Name some precautions taken to prevent being affected by Iodine-131.
Answer- Tongs/Special Suits.
e. What emitter is used for paper rollers?
Answer - Beta emitter.
f. How does this system work?
The beta roller passes through the paper and the detector keeps a track on how many beta particles pass through. If the paper is too thick, beta count drops and the detector sends a signal to reduce pressure on the paper. If the paper is too thin, beta count is too high and the detector sends a signal to increase pressure on the paper.

Q4. Rollercoaster Question
a. 2.37 million/1.71 million
b. 1.71 million.
c. Energy transfer when the rollercoaster moves from C to D.
GPE to Kinetic Energy, as it loses its GPE as it moves downward and according to conservation of energy, it changes to kinetic energy.
d.
e.

Q5. Volts Question
a. Draw the voltmeter.
b. 12 Volts can be written as :
Answer - 12 Joules per coulomb.
c. Prove that the resistance is 11 ohms.
Answer- The resistance was 10.8 ohms, which is about 11 ohms
d.D
e. Six marker on filament lamp.

Q6. Acceleration
a. Acceleration of the graph.
Answer : y/x to get gradient = 6 m/s^2
b. Draw the graph for a cyclist with a smaller acceleration.
c. Why does the cyclist need to keep pedaling?
Answer- To overcome air resistance and maintain the same velocity.

Reply 104

fluctuation_0

The answer is D for the Ammeter and Voltmeter question. Ammeter = increase, Voltmeter = decrease.

Reply 105

SophFlorence

Original post by fluctuation_0

The answer is D for the Ammeter and Voltmeter question. Ammeter = increase, Voltmeter = decrease.

That was C, but yeah. D said both decrease.

Reply 106

Penguin_S

Original post by TSRPAV

what was the question?

The question was: What will happen to the current and voltage of the resistance is increased? I ticked decrease decrease so option c

Reply 107

zoeolo

I didn't say it heats up because of electrons colliding with the ions in the lattice but I did everything else! How many marks do you think I will get? 4-5 / 6?

Posted from TSR Mobile

Reply 108

Penguin_S

Original post by fluctuation_0

The answer is D for the Ammeter and Voltmeter question. Ammeter = increase, Voltmeter = decrease.

I thought that the answer would be d at first but if resistance increases the the current will decrease which will lead to the voltage to decrease because current and voltage are directly proportional

Reply 109

Lemuelc14

It couldn't have been that because the decay is exponential so it wouldn't be a linear decrease so you can't just add 80. I thought that because it had a half life of 8 days, to estimate 7 days before you'd just multiply 180 by 2 to get 360?

Reply 110

grace143

kinda sucks when you give a few answers and they get used in the markscheme but there is no rep / quote / mention of it.....

Reply 111

J__

For the transfer of energy question about the rollercoaster from C to D, wasn't it the other way around. KPE --> GPE + thermal and sound ??

Reply 112

J__

And for the safety precaution, I said a lead screen to absorb the radiation. Will I get the mark?

Reply 113

Tsr74

Original post by J__

For the transfer of energy question about the rollercoaster from C to D, wasn't it the other way around. KPE --> GPE + thermal and sound ??

Yes it was. C -> D was going upwards. The higher you get the more GPE you have, this energy is transferred from KE as KE lost equals GPE gained.

(edited 7 years ago)

Reply 114

DamnDaniel2

Yayyy based on this mark scheme only lost 2 marks (not including the estimation one).

For the estimation one, I put 260 but then thought it was too small and then put 300 lol.

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Reply 115

Tsr74

Original post by Penguin_S

The circuit had a constant power source, so if the current decreased the voltage would have to increase.

(edited 7 years ago)

Reply 116

TSRPAV

Original post by Penguin_S

The question was: What will happen to the current and voltage of the resistance is increased? I ticked decrease decrease so option c

Did it say that anything was kept constant or anything except the resistance changed? cos current is inversely proportional to resistance so as the resistance rises the current decreases assuming potential difference stays the same

(edited 7 years ago)

Reply 117

TSRPAV

Original post by Dylanuk16

For the question about how hospital staff take precautions i put standing behind a glass window. Will i still get mark?

Only beta can be absorbed by an optically dense glass medium so if the source was gamma in the question which im pretty sure they would use you wouldn't get the mark,if it was more than 1 mark question you may get something.