Physics [1 Mark Question Answer]

The resistance offered by the electrolyte of a cell is called its internal resistance.

Ohmic resistances are the resistances which obey Ohm's law, i.e., the value of V/I is a constant quantity for all values of V and I . The graph between potential difference and the current flowing through a conductor, is a straight line. Examples: Copper and aluminium.
The resistors which do not obey Ohm's law are known as non-ohmic resistances. The graph between potential difference and current for such resistors is not a straight line. Example : ionic conductors, electronic valves, coil of an electromagnet.

Superconductors are the substances, whose resistance is almost zero. Mercury is a superconductor at temperature below 4.2 K. Lead is a superconductor below 7.25 K .

The number of charges which drif from a higher to a lower potential is called quantity of charge. The unit of quantity of electric charge is coulomb (C).
1 C is the quantity of electric charge which will deposit 0.00118 g of silver on the cathode, when passed through silver nitrate solution.

(a) Conventional current flows from higher potential (positive terminal) to a lower potential (negative terminal). Electronic current flows from lower potential to a higher potential i.e., from negative terminal to positive terminal.
(b) Manganin, constantan