Help With Science (1 Viewer)

[Kabuzo01]

Hey everyone, I dont quite understand this question, an explanaition of it would be great ^_^

http://www4.boardofstudies.nsw.edu.au/testResults.cfm?testID=7166938&testUUID=66A07606-C71E-9B9C-A2B5F012EC6059AD&question_id=1319&question_num=13&correctAnswer=A&user_answer=B&courseID=5020&testQuestionID=141000438

 

[ShireFolk]

join the club

 

[Jumper :^)]

Metals expand when they're heated, and different metals may expand at different rates. The bi-metal strip in the diagram is made of two different metals (metal 1 and metal 2), and when the strip is heated, one of the metals will expand more than the other, forcing the strip to bend.

When you put the two complete sequences in the table together (the top 2 rows), you get:

Electricity flows -> Bi-metal strip gets hot -> Bi-metal strip bends -> Gap opens -> Electricity stops flowing.

From that you can see that when the strip bends, the gap opens. That means that when the strip is heated, it must bend away from the contact in the digram, not towards it.
So the metal on top- metal 1- must have expanded more than metal 2.

So the answer is A) Away from the contact because metal 2 expands less than metal 1.

Hope that wasn't too confusing...

 

[Kabuzo01]

Very confusing but I understand it now, thanks. ^_^