When a gas filled in a closed vessel is heated by raising the temperature by 1$$^\circ$$C, its pressure increases by 0.4%. The initial temperature of the gas is ___________ K.
A steam engine intakes 50 g of steam at 100$$^\circ$$C per minute and cools it down to 20$$^\circ$$C. If latent heat of vaporization of steam is 540 cal g$$-$$1, then the heat rejected by the steam engine per minute is __________ $$\times$$ 103 cal.
(Given : specific heat capacity of water : 1 cal g$$-$$1 $$^\circ$$C$$-$$1)
A monoatomic gas performs a work of $${Q \over {4}}$$ where Q is the heat supplied to it. The molar heat capacity of the gas will be ______________ R during this transformation. Where R is the gas constant.
In an experiment to verify Newton's law of cooling, a graph is plotted between the temperature difference ($$\Delta$$T) of the water and surroundings and time as shown in figure. The initial temperature of water is taken as 80$$^\circ$$C. The value of t2 as mentioned in the graph will be __________.