A silver wire of length 2m and radius 1mm is joined in series with an iron wire of length "4m" and radius "3mm" and a current is passed through the wires. The ratio of the current density in the silver and iron wires is

A copper wire of length 1 m and radius is joined in series with an iron wire of length 2 m and radius 3 mm and a current is passed through the wire. The ratio of the current density in the copper and iron wires is

When current is passed through a wire wound around an iron rod, it produces

A wire of length 1 m and radius 1 mm is welded to another wire of length 2 m and radius 2 mm the free end of the first is clamped and aload of 5kg ispplied at the free end of the second wire . What is the total increase of the compound wire ? (Y of both wires =2xx10^(11) ""Nm^(-2) )

The same mass of copper is drawn into two wires 2 mm and 3mm thick. The two wires are connected in series and current is passed through them. The ratio of heat produced in the two wires is

The same mass of copper is drawn into two wires 2mm and 3mm thick,. The two wires are connected in series and current is passed through them. The ratio of heats produced in the two wires is-

A wire of length 1 m and radius 0.1mm gas a resistance of 100(Omega) .Find the resistivity of the material .

An aluminium wire of diameter 2.5 mm is connectedf in series with a copper wire of diameter1.6 mm. A current of 2.0 A is passed through them. Find (a) current density in aluminium wire, (b) drift velocity of electrons in copper wire. Given the number density of conduction electrons in copper is 10^(29) m^(-3) .

The resistance of a wire of length 40 m and radius o.25 mm is 10 Omega . The conductivity of the material of the wire is

The same mass of aluminium is draw into two wires 1mm and 2mm thick . Two wires are connected in series and current is passed through them. Heat produced in the wires is in the ratio.

Same mass of copper is drawn into 2 wires of 1 mm thick ad 3 mm thick. Two wires are connected in series and current is passed. Heat produced in the wires is the ratio of