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

A copper wire has a diameter of 0.5 mm and a resistivity of 1.6×10^−6 ohm-m. How much of this wire would be necessary to make a resistance of 10 ohm?

Calculate the resistivity of a wire having resistance .02 ohm, length = 10 m and area = 1mm^2

A potentiometer wire of length 100 cm has a resistance of 10 ohm. It is connected in series with a resistance and a battery of emf 2V and of negligible internal resistance. A source of emf 10mV is balanced against a length of 40 cm of the potentiometer wire. What is the value of the external resistance?