(1) A wire of 3 ohm resistance and 10 cm length is stretched to 30 cm length. Assuming that it has a uniform cross section, what will be its new resistance?
(2) A wire of 9 ohm resistance having 30 cm length is tripled on itself. What is its new resistance?
(3) What length of copper wire of resistivity 1.7x10-8ohm metre and radius 1mm is required so that its resistance is 1 ohm?