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National 5 Physics 2015-2016

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Original post by A+Hunter
It was 4 marks yeah. i can remember it clearly being 4


Okay, Thanks man :biggrin:
How was half life 0.75kbq?
Original post by Med_Diablo
How was half life 0.75kbq?


Activity was 0.75kBq
Original post by Med_Diablo
How was half life 0.75kbq?


or 750 Bq
Original post by A+Hunter
Activity was 0.75kBq

Oh ok whatd you getrir half life then?
Original post by Med_Diablo
Oh ok whatd you getrir half life then?


They gave u the half life in the question. It was like 36 hours or something like that
What did you guys get for the question where they gave you a current/voltage graph and you had to comment on the resistance?

It was only one mark but i got confused :/
Also what about the question about the washing machine where it gave you a circuit with a transistor and you had to explain how the heating element would switch off?
Original post by A+Hunter
Activity was 0.75kBq


Activity after 144 hours is what you had to calculate with the initial activity being 12kBq and the 36 hours half life meaning every 36 hours it halved so you half it 4 times to get 0.75kBq

@Med_Diablo
Original post by alex5023
What did you guys get for the question where they gave you a current/voltage graph and you had to comment on the resistance?

It was only one mark but i got confused :/


Yeah what did everyone write for this question ?
Original post by sameehaiqbal
Activity after 144 hours is what you had to calculate with the initial activity being 12kBq and the 36 hours half life meaning every 36 hours it halved so you half it 4 times to get 0.75kBq

@Med_Diablo


Yeah
Original post by alex5023
What did you guys get for the question where they gave you a current/voltage graph and you had to comment on the resistance?

It was only one mark but i got confused :/


Original post by Ethan100
Yeah what did everyone write for this question ?


Increase/decrease the resisitance that's what i wrote.
Original post by A+Hunter
Increase/decrease the resisitance that's what i wrote.


Increase and decrease ? How both of them ?
Original post by alex5023
What did you guys get for the question where they gave you a current/voltage graph and you had to comment on the resistance?

It was only one mark but i got confused :/


I mentioned that the resistance was increasing but not at a constant rate this is because of the temperature of of the lamp. I don't think I was specific enough though.

http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel_pre_2011/electricityintheory/voltagecurrentresistancerev5.shtml

The filament lamp graph on bitesize explains it
Original post by Ethan100
Increase and decrease ? How both of them ?


I wrote increase or decrease the resisitance (was meant to write the resistance of the variable resisitor) in order to gain different values of the current+voltage.

When resisitance goes up, current goes down and vice versa
Original post by A+Hunter
I wrote increase or decrease the resisitance (was meant to write the resistance of the variable resisitor) in order to gain different values of the current+voltage.

When resisitance goes up, current goes down and vice versa


I just wrote the resistance will increase
is that correct ?
Yeah I just talked about how voltage and current was not directly proportional so the lamp doesn't follow ohm's law
Original post by Ethan100
I just wrote the resistance will increase
is that correct ?


Wait qhat question is this lol :P I'm lost
i just said the resistance will increase when both the current and the voltage increase.

is that right??
If anyone has the paper, I'll look at it!

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