If this resistor is made of a material of cross- sectional area 4×10^-4cm^2 and resistivity 2×10^-6ohmcentimeter, calculate its length?

The units involved should tell you how to use these constants along with the resistance..

(Ω-cm^2) / (Ω-cm) = cm

To calculate the length of the resistor, we can use the formula:

Resistance = (Resistivity * Length) / Cross-sectional area

Given that the resistivity is 2×10^-6 ohm-centimeter and the cross-sectional area is 4×10^-4 cm^2, we can substitute these values into the formula.

Resistance = (2×10^-6 ohm-cm * Length) / (4×10^-4 cm^2)

Now, we need to rearrange the formula to solve for the length.

Length = (Resistance * Cross-sectional area) / Resistivity

Plugging in the values, we get:

Length = (Resistance * 4×10^-4 cm^2) / (2×10^-6 ohm-cm)

Since the resistance is not given in the question, we need that value to calculate the length of the resistor.