When 0.81 m of a wire with cross-sectional area of 3.1*10^-11 m^2 is connected across a 2 V battery a current of 1.6 A flows in the wire. Find the resistivity of the material of the wire.
The resistance in the wire is given by the resistivity of the material by the lenght and divided by the cross-sectional area (R = pL/A). From here we can rearrange and have p = RA/L. However, we also know that R = V/I, and thus, our final formula becomes p = VA / IL. Plugging in the numbers we get p = 23.110^-11 / 1.60.81, which is equal to 4.7839510^-11, or rounding, 4.8*10^-11 Ohm-meters.
VB
Related Physics A Level answers
All answers ▸The braking distance of a road train travelling at 15m/s is 70m. Assuming that the same braking force is applied at all speeds, show that the braking distance of a road train when travelling at 25m/s is about 190m.
What are quarks?
How can I describe the motion of an object falling, due to gravity, through a fluid? And when does the object reach terminal velocity?
How does energy flow from voltage source to resistor in a simple DC circuit?