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 student measures the terminal potential difference (V) of a cell (of emf $$\varepsilon $$ and internal resistance r) as a function of the current (I) flowing through it. The slope, and intercept, of the graph between V and I, then respectively, equal

In the circuit shown, the current through the 4 $$\Omega $$ resistor is 1 amp when the points P and M are connected to a d.c. voltage source. The potential difference betwen the points M and N is

A wire of a certain material is stretched slowly by ten percent. Its new resistance and specific resistance become respectively