Write the ratio of the maximum and minimum time observed in the universe.

Calculate the solid angle subtended by the periphery of an area of $1 \, cm^2$ at a point situated symmetrically at a distance of $5 \, cm$ from the area. (in $, sr$)

Which method is used in the modern era to measure the distance of a nearby planet from the Earth?

Which of the following is the most precise device for measuring length?

Suppose you have taken a dilute solution of oleic acid in such a way that its concentration becomes $0.01 \, cm^3$ of oleic acid per $cm^3$ of the solution. Then you make a thin film of this solution (monomolecular thickness) of area $4 \, cm^2$ by considering $100$ spherical drops of radius $\left(\frac{3}{40 \pi}\right)^{1/3} \times 10^{-3} \, cm$. Then the thickness of the oleic acid layer will be $x \times 10^{-14} \, m$. Where $x$ is ...... .

Define the unit of mass in nuclear physics. Explain the measurement of the mass of a body.