$A$ cuboidal block has dimensions $(1.5 \times 1.5 \times 1.0) \ cm$. What is the total surface area of the cuboid (in $cm^2$)?

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 $, sr$)

The moon is observed from two diametrically opposite points $A$ and $B$ on Earth. The angle $\theta$ subtended at the moon by the two directions of observation is $1^{\circ} 54^{\prime}$. Given the diameter of the Earth to be about $1.276 \times 10^{7} \; m$,compute the distance of the moon from the Earth.

What is mass? Write the effect of external factors on mass.

It is claimed that two cesium clocks,if allowed to run for $100$ years,free from any disturbance,may differ by only about $0.02\; s$. What does this imply for the accuracy of the standard cesium clock in measuring a time-interval of $1\; s$?

In an experiment,a set of readings are obtained: $1.24 \ mm, 1.25 \ mm, 1.23 \ mm, 1.21 \ mm$. The expected least count of the instrument used in recording these readings is . . . . . . $mm$.