GCSE AQA 9-1 Physics Paper 1 Discussion Watch
(I got 1000 ohms for the resistance of the LDR - did anyone else get the same thing?)
Edit: our paper is in the Wikipedia article for "banana equivalent dose"
That would be true for a series but in this case it wasn't a series as the voltage was not equal. I got 6000 ohms but i think thats wrong. The rest of the paper was easy, however.
The current is the same everywhere in series so R=V/I so 4/0.004=1000
2 marks on the resistance Q
3 marks on the directly proportional what happens when power halves question
One mark on a tick box question one
Got the rest of the maths right tho.
7.50 for the last question
13.35 count rate
Percentage change like 15. Something percent
First question I said electrons are transferred from the carpet to the socks causing the negative charge as it gains electrons
Then lines inward
Then I said pd between the metal tap (earthed conductor) is at 0V and the sock is charged so there is a pd. if the pd gets big enough air is ionised so electrons can jump across gap for spark to form which causes an electric shock.
The energy transfer question was:
what do u think grade boundaries will be
The question about circuit was just add ammeter to the left hand side of the original circuit and attach voltmeter around the wire