A potentiometer circuit is set up as shown. The potential gradient, across the potentiometer wire, is k volt/cm and the ammeter, present in the circuit, reads 1.0 A when two way key is switched off. The balance points, when the key between the terminals (i) 1 and 2 (ii) 1 and 3, is plugged in, are found to be at length $$l$$₁ cm and $$l$$₂ cm respectively. The magnitudes, of the resistors R and X, in ohms, are then, equal, respectively, to

Consider the following two statements.
(A)  Kirchoff's junction law follows from the conservation of charge.
(B)  Kirchhoff's loop law follows from the conservation of energy.

Which of the following is correct?

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

A wire of resistance 12 ohms per meter is bent to form a complete circle of radius 10 cm. The resistance between its two diametrically opposite points, A and B as shown in the figure is