Explain why :

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

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

$(c)$ an optical pyrometer (for measuring high temperatures) calibrated for an ideal black body radiation gives too low a value for the temperature of a red hot iron piece in the open, but gives a correct value for the temperature when the same piece is in the furnace

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

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

If an electric heater is rated at $1000\,W$, then the time required to heat one litre of water from $20\,^oC$ to $60\,^oC$ is

A pendulum clock keeps correct time at $0\,^oC$. The thermal coefficient of linear expansion of the material of the pendulum is $\alpha $. If the temperature rises to $t\,^oC$, then the clock loses per day by (in second)

A faulty thermometer has its fixed points marked $5^o$ and $95^o$. This thermometer reads the temperature of a body as $59^o$. Then, the correct temperature of the body on the Celsius scale is …… $^o$

Amount of heat required to raise the temperature of a body through $1 ^o C$ is called its