In the circuit shown in the figure, if the potential at point A is taken to be zero, the potential at point B is

A current of 2 A flows through a 2 $$\Omega $$ resistor when connected across a battery a 2 $$\Omega $$ resistor when connected across a battery. The same battery supplies a current of 0.5 A when connected across a 9 $$\Omega $$ resistor. The internal resistance of the battery is

If power dissipated in the 9 $$\Omega $$ resistor in the circuit shown is 36 watt, the potential difference across the 2 $$\Omega $$ resistor is

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