A copper wire of resistivity `1.6xx10^-8 ohm-m` has a cross sectional area of `20xx10^-4 cm^2`. Calculate the length of wire required to make a 10 ohm coil.

A steel wire of length 4.7 m and cross-sectional area 3.0 xx 10^-5 m^2 stretches by the same amount as a copper wire of length 3.5 m and cross-sectional area of 4.0 xx 10^-5 M^2 under a given load. What is the ratio of the Young’s modulus of steel to that of copper?

A 14.5 kg mass, fastened to the end of a steel wire of unstretched length 1.0 m, is whirled in a vertical circle with an angular velocity of 2 rev//s at the bottom of the circle. The cross-sectional area of the wire is 0.065 cm^2 . Calculate the elongation of the wire when the mass is at the lowest point of its path.

A copper wire has diameter 0.5 mm, and resistivity of 1.6xx10^-8 ohm -m . What will be the length of this make its resistance 10 ohm ? How much does the resistance change if the diameter is doubled.

A copper has 80xx10^28 per cubic metre. A copper wire of length 1m and cross-sectional area 8.0xx10^-6m^2 carrying a current and lying at right angle to a magnetic field of strength 5xx10^-3T experiences a force of 8.0xx10^-2N. Calculate the drift velocity of free electrons in wire.

A stress of 10^7 N m^-2 is required to break a material of density 4 xx 10^4 kg m^-3 . Calculate the length of a wire of this material, which can break under its own weight.

A uniform copper wire of mass 2.23xx10^(-3) kg carries a current of 1 A when 1.7 V is applied across it. Calculate its length and area of cross-section. If the wire is uniformly stretched to double its length, calculate the new resistance. Density of copper is 8.92xx10^(3) kg m^(-3) and resistivity is 1.7xx10^(-8) Omega m.