One likes to sit under sunshine in winter season, because

Which of the following statements is/are $CORRECT$ Correct option are

$(i)$ a body with large reflectivity is a poor emitter

$(ii)$ a brass tumbler feels much colder than a wooden tray on a chilly day

$(iii)$ the earth without its atmosphere would be inhospitably cold

$(iv)$ heating systems based on circulation of steam are more efficient in warming a building than those based on circulation of hot water

The ratio of thermal conductivity of two rods of different material is $5 : 4$ . The two rods of same area of cross-section and same thermal resistance will have the lengths in the ratio

$Assertion :$ Two thin blankets put together are warmer than a single blanket of double the thickness.
$Reason :$ Thickness increases because of air layer enclosed between the two blankets.

$A$ wall is made up of two layers $A$ and $B$ . The thickness of the two layers is the same, but materials are different. The thermal conductivity of $A$ is double than that of $B$ . In thermal equilibrium the temperature difference between the two ends is ${36^o}C$. Then the difference of temperature at the two surfaces of $A$ will be ....... $^oC$

When two ends of a rod wrapped with cotton are maintained at different temperatures and after some time every point of the rod attains a constant temperature, then