A copper wire has a diameter of `0.5 mm` and a resistivity of `1.6 xx 10^-6 Omegacm`. How much of this wire would be required to make a `10 Omega` coil ? 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 xx 10^-6 ohm cm. How much of this wire would be required to make a 10 ohm coil ? How much does the resistance change if the diameter is doubled ?

What length of a wire of diameter 0.46 mm and specific resistance 50xx10^(-6) Omega m would be required to make a coil of resistance 10 Omega ?

A small insect crawls in the direction of electron drift along bare copper wire that carries a current of 2.56A. It travels with the drift speed of the electron in the wire of uniform cross-section area 1mm^2 Number of free electrons for copper = 8 times 10^28// cc and resistivity of copper = 1.6 times 10^-8 Omega m How much time would the insect take to crawl 1.0 cm if it crawls at the drift speed of the electron in the wire?

A 1m long wire of diameter 0.31mm has a resistance of 4.2 Omega . If it is replaced by another wire of same material of length 1.5m and diameter 0.155 mm , then the resistance of wire is

A coil of 50 turns and 20 cm diameter is made with a wire of 0.2 mm diameter and resistivity 2xx10^(-6)Omega cm .The coil is connected to a source of EMF . 20 V and negligible internal resistance. (a)Find the current through the coil. (b)What must be the minimum potential difference across the coil so as to nullify the earth's horizontal magnetic induction 3.14xx10^(-5) tesla at the centre of the coil.How should the coil be placed to achieve the above result.