$Parsec$ is a unit of

It is estimated that per minute each $cm^2$ of the Earth receives about $2 \ cal$ $(1 \ cal = 4.18 \ J)$ of heat energy from the Sun. This is called the Solar constant. In $SI$ units,the value is: (in $W/m^2$)

Which of the following is a derived unit?

Give information for the units of pressure $torr$ and $bar$.

Number of base $SI$ units is

$A$ micron is related to a centimetre as: