Current Electri...

An electric wire of length ‘L’ and area of cross-section a has a resistance R ohm. Another wire of the same material having same length and area of cross-section 4a has a resistance of

For which of the following the resistance decreases on increasing the temperature?

If n, e, τ and m respectively represent the density, charge relaxation time and mass of the electron, then the resistance of a wire of length land area of cross-section A will be

Which of the following statements is correct?

A certain piece of silver of given mass is to be made like a wire. Which of the following combinations of length (L) and the area of cross-section (A) will lead to the smallest resistance

A metal wire of specific resistance 64 × 10^–6 ohm-cmand length 198 cm has a resistance of 7 ohm, the radius of the wire will be

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

For a metallic wire, the ratio V/i (V = the applied potential difference, i = current flowing) is

Which of the following has a negative temperature coefficient?

The reciprocal of resistance is