A needle electrode made of an unknown material is produced to function as an electrode and for injection if needed. The wall thickness of the electrode is constant, and it is t 0.1 mm everywhere. The shaft and the truncated cone head dimensions are given as r=0.2 mm, 691 mm, L, 2 mm, and L = 100 mm. If the resistance of the needle electrode measured between tip (A) and base (8) is 10 Ohm, calculate the material's conductivity. O 0 I