AQA GCSE Combined science Physics trilogy 23rd May 2018 Unofficial Markscheme

Q2) why do all elements have the same positive charge as other atoms of that element?

I put because atoms of the same element all have the same amount of protons, so therefore the same positive charge as each other because protons are positively charged. Anyone else put that?? Not sure if it’s enough to get the 3 marks

Sorry I don't remember the question numbers.

what does 15mj mean

Also what did you guys get for the 6 marker to find charge?

the practical question was easy was about density
you menna say
put the object on the balance and weigh it
then put it in a eureka can filled with water and place a measuring cylinder next to it the volume of the object is in the measuring cylinder plug the mass and volume into density equation and find out the density

how many marks do u think is that out of 6

The charge question was 60C, the question gave you the power and resistance for one of the lamps, you had to work out the current (which was 0.5A) and then multiply by 2 because there were 2 lamps, then you had to multiply it by the time (60s) which gave you the final answer of 60C.

FINALY someone that used that formula. I got worried that I was the only one

uncertainty was 40 right?

30 for charge but I realised at the end it was 60 as it is in parallel so total current = I(1) +I(2)
The last six marker was LDR and as light intensity increased the current increased and the voltage decreased

I got 30 for charge, you had to use the two equations “power = current^2 x resistance” and “charge = current x time” and rearrange them or whatever. Could someone explain the uncertainty question please? Just guessed it

you find the range of the values which was 80 and then divide by 2 which gave u 40 for the uncertainty

Did the question have a diagram?