Measuring The Resistivity Of A Pencil Lead.

The first 200 words of this essay...

PHYSICS COURSEWORK 16TH JANUARY 2003

Measuring The Resistivity Of A Pencil Lead

Hypothesis

The resistance of two objects is not always the same due to "resistivity". The resistance of a uniform conductor depends on :

* Its length (L)

* Its cross-sectional area (A)

* The material of which it is made

Therefore, the relationship between these three variables and resistance is as follows:

Where : - R = Resistance

P = Resistivity

L = Length

A = Cross-sectional Area

Resistivity is defined as a materials opposition to the flow of electric current of a cubic metre of a material.

To measure the resistivity of pencil lead I will need the following apparatus.......

* 1 x Power Pack (Ranging from 2V - 12V)

* 1 x Voltmeter (Reading up to 20V, giving readings to 0.00 with a ?3% error reading)

* 1 x Ammeter (Reading 20m/10A, giving readings to 0.00 with a ?0.5% error reading)

* 1 x Rheostat

* 1 x Micrometer (with an error reading of ? 0.005mm)

* 1 x Metre rule (with mm