The $SI$ unit of pressure is:

Universal time is based on:

Fill in the blanks:
$(a)$ $1 \, rad = \dots \text{ degrees}$
$(b)$ Light year is a unit of $\dots$
$(c)$ The solid angle subtended by a hemisphere at its center is $\dots$

One yard in $SI$ units is equal to:

How many wavelengths of $Kr^{86}$ are there in one metre?

$1\,g\,cm^{-3} = ....\,kg\,m^{-3}$