The length and diameter of a wire about 1 metre long are measured.The diameter is measured at 10 different places with a micrometer screw gauge and the mean diameter is calculated.This is used to calculate the cross-sectional area of the wire using A = π(d/2)2.The length of the wire is measured with a metre rule.The wire is passed over a pulley and attached to a slotted mass holder. Using increasing force as the independent variable, slotted masses are added and the corresponding extension (the dependent variable) is measured from the movement of a marker on the wire against a fixed rule.Plot stress against strain.Gradient = E (Young modulus).