Physics help =)

[Unkownbunny]

Hiya guys x

sorry to bother but i need some help
http://www.xtremepapers.me/CIE/Cambridg ... qp_3_2.pdf

8(c) (ii)
9(c) (ii)
10 (c) (ii) i got 0 then second 1? how is it on and off? im lost =)
Thanks for all the help
and please if you have any notes please share xxx

 

[Keeemoman]

Which varient

 

[Unkownbunny]

im so sorry i forgot to mention it. Varient 32.
I get everything else except for the force exerted on the wire for 9 c ii

 

[Keeemoman]

OK you know that any current carrying conductor contains a magnetic field
Therefore it would attract as you know any two objects having different poles attract
If you draw the diagram in b you would get the magnetic field going opposite direction which allow them to attract

 

[Unkownbunny]

i understand that but why to the right?

 

[Unkownbunny]

i understand that but why to the right?

 

[unplugged]

You can imagine the wires as forming poles around themselves. Becoming like two magnets. Now since the current in both wires is in the same direction. Each pole is form on the same corresponding side.
So the left side of the thick wire has a different pole than the right side of the thin wire and hence the two wires attract just like two magnets would.

 

[unplugged]

For the last one. NOR gate will return a high input only if both inputs are low. So when the heater isn't working it returns LOW and when the pressure is low it returns LOW. So light works.
When Heating is working is returns HIGH and when pressure is high it returns HIGH so both inputs are high and therefore the NOR gate returns LOW.