Every conductor has resistance that depending on the following factors:
1). it varies direcly as its length, l
2). it varies inversely as the cross-section A of the conductor.
3). it depends on the nature of material.
4). it depending on the temperature of the conductor.
Ignoring the last factor fo the time being, we can say that:
where:
"R" is resistance of the conductor (ohm) "READ : The Unit of Resistance"
"l" is the length of the condutor (metre)
"A" is the area of cross section of the conductor (metre^2)
is a constant depending on the nature of the material of the conductor known as its specific resistance or resistivity, that will be discussed in Unit of Resistivity
from the equetion above, we will know how to get good conductor. good conductors those with little resistace. "READ ALSO: good resistance in Modern Electron Theory".
statemen 1
the longger the conductor the greater the resistance and vice verse the shorter conductor the smaller the resistance.
statemen 2
statement 2 is contradict statement 1. stattemen 2 said the greater the cross area (A) of the conductor the smaller the resistance and vice verse the smaller the cross area (A) of the conductor the greater the resistance.
from the equetion above, we will know how to get good conductor. good conductors those with little resistace. "READ ALSO: good resistance in Modern Electron Theory".
statemen 1
the longger the conductor the greater the resistance and vice verse the shorter conductor the smaller the resistance.
statemen 2
statement 2 is contradict statement 1. stattemen 2 said the greater the cross area (A) of the conductor the smaller the resistance and vice verse the smaller the cross area (A) of the conductor the greater the resistance.
figure 1
figure 2
figure 3
1) Compare figure 1 and figure 2, which figure that has smaller resistance?
2) Compare figure 2 and figure 3, which figure that has smaller resistance?
"you write your answer in comment comment field"
Unit of Resistivity
resistivity is the nature material of conductor. the equetion of resistivity:
Where:
"m" is mass of thing (kg)
"V" is volume of the thing (m^3)
S.I. system of units resistivity is ohm-metre.
It may, however, be noted that resistivity is sometime expressed as so many ohm per m^3. although it is incorrect to say so, but it means the same thing as ohm-metre. if 'l' in centimetres and A in cm^3, then
in ohm-centimetre.
Values of resistivity and temperature coefficients for various materials are given in table below.
2) Compare figure 2 and figure 3, which figure that has smaller resistance?
"you write your answer in comment comment field"
Unit of Resistivity
resistivity is the nature material of conductor. the equetion of resistivity:
Where:
"m" is mass of thing (kg)
"V" is volume of the thing (m^3)
S.I. system of units resistivity is ohm-metre.
It may, however, be noted that resistivity is sometime expressed as so many ohm per m^3. although it is incorrect to say so, but it means the same thing as ohm-metre. if 'l' in centimetres and A in cm^3, then
in ohm-centimetre.Values of resistivity and temperature coefficients for various materials are given in table below.
Table of resistivity and temperature coefficient
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