Measuring Resistivity Flashcards
1
Q
What apparatus do you need?
A
Wire Micrometer Metre rule Power Supply Ammeter Voltmeter
2
Q
What does the micrometer measure? What can you work out from this?
A
Diameter, so you can work out area
3
Q
How many places should you measure the diameter?
A
At least 3
4
Q
What 2 things could you change?
A
Length or area
5
Q
Why should you only pass current through the wire for a short time?
A
So it doesn’t get hot- changes the resistivity and a potential burn hazard
6
Q
If varying length, what should be on x and y?
A
x- length
y- resistance
7
Q
If varying length, what will the gradient be?
A
p/A
8
Q
If varying length, how can you work out p?
A
Multiply gradient by the cross sectional area
9
Q
If varying area, what should be on x and y?
A
x- l/A
y- R
10
Q
If varying area, what will the gradient be?
A
pl
11
Q
If varying length, how can you work out p?
A
Divide gradient by length of wire
