The change in the magnitude of the volume of an ideal gas when a small additional pressure $$\Delta $$P is applied at a constant temperature, is the same as the change when the temperature is reduced by a small quantity $$\Delta $$T at constant pressure. The initial temperature and pressure of the gas were 300 K and 2 atm. respectively.
If |$$\Delta $$T| = C|$$\Delta $$P| then value of C in (K/atm.) is _________.

In a photoelectric effect experiment, the graph of stopping potential V versus reciprocal of wavelength obtained is shown in the figure. As the intensity of incident radiation is increased :

Identify the operation performed by the circuit given below :

Four resistances 40 $$\Omega $$, 60 $$\Omega $$, 90 $$\Omega $$ and 110 $$\Omega $$ make the arms of a quadrilateral ABCD. Across AC is a battery of emf 40 V and internal resistance negligible.The potential difference across BD in V is _______.