If a gas is compressed isothermally,then the r.m.s. velocity of the molecules

The increasing order of the atomic radius of $Si, S, Na, Mg, Al$ is

Which of the following is a characteristic of a prokaryotic organism?

The magnetic susceptibility of the material of a rod is $499$. Permeability of vacuum is $4 \pi \times 10^{-7} \ H/m$. Absolute permeability of the material of the rod in $H/m$ is:

The energy of a photon is $3 \times 10^{-12} \ erg$. What is its wavelength in $nm$?
$(h = 6.62 \times 10^{-27} \ erg \cdot s; c = 3 \times 10^{10} \ cm/s)$

The number of ways that $8$ beads of different colours can be strung as a necklace is