Current Electricity Quiz-1

A battery of 24 cells each of emf 1.5 V and internal resistance $2\Omega$ is connected so as to send maximum current through a 12 resistance. In order to achieve this we must connect.

The mean free path of electrons in a metal is $4 \times 10 ^{-8}\,m.$ The electric field which can give on an average 2eV energy to an electron in the metal will be in the units V/m.

The length of a wire is doubled and current through it is increased by a factor of $\frac32$ without any change of temperature. The resistivity of the material of the wire

A copper wire is stretched to make it 0.1% longer. Then the percentage change in its resistance is

Which of the following statement is correct?

Which of the following statements is incorrect?

To obtain the optimum sensitivity of a Wheatstone bridge, for a given ‘want of balance’, and with a freedom of choice of arrangement, we should.

Two wires, made of tinned copper, having identical cross section and different lengths, are used as fuses. Then

A fuse, with a radius of 0.1 mm blows at 10A. What should be the radius of fuse wire made of the same material which melts at 20A?

A piece of silver and another of germanium cooled from room temperature to 85K. Then the resistance of