10 divisions on the main scale of a Vernier calliper coincide with 11 divisions on the Vernier scale. If each division on the main scale is of 5 units, the least count of the instrument is :

Two moles a monoatomic gas is mixed with six moles of a diatomic gas. The molar specific heat of the mixture at constant volume is :

The dimensional formula of angular impulse is :

A monochromatic light of wavelength $6000 ~\mathring{A}$ is incident on the single slit of width $0.01 \mathrm{~mm}$. If the diffraction pattern is formed at the focus of the convex lens of focal length $20 \mathrm{~cm}$, the linear width of the central maximum is :