An aluminium (respectively `p = 2.2 xx10^8 Omega -m`) wire of a diameter 1.4 mm is used to make a `4Omega` resister . The length of the wire is

Calculate the length of a wire of diameter 1 mm needed to prepare a coil of resistance 25 ohm. The resistivity of the material of the wire is 3.14 times 10^(-7) Omega.m .

The resistance of a wire of length 31.4 m and diameter 1 mm is 20 Omega . Find the resistivity of the material of the wire.

A copper wire has diameter 0.5 mm and resistivity of 1.6 xx 10^(–8) Omega m. What will be the length of this wire to make its resistance 10 Omega ? How much does the resistance change if the diameter is doubled?

A hollow cylinder (rho=2.2 xx 10^(-8)Omega-m) of length 3 m has inner and outer diameters are 2 mm and 4 mm respectively. The resistance of the cylinder is

A hollow cylinder (rho=2.2xx10^(-8)Omega-m) of length 3 m has inner and outer diameters are 2 min and 4 mm respectively. The resistance of the cylinder is