If $$\mathrm{n}$$ is the number density and $$\mathrm{d}$$ is the diameter of the molecule, then the average distance covered by a molecule between two successive collisions (i.e. mean free path) is represented by :

The electric field at point $$\mathrm{p}$$ due to an electric dipole is $$\mathrm{E}$$. The electric field at point $$\mathrm{R}$$ on equitorial line will be $$\frac{\mathrm{E}}{x}$$. The value of $$x$$ :

A sonometer wire of resonating length $$90 \mathrm{~cm}$$ has a fundamental frequency of $$400 \mathrm{~Hz}$$ when kept under some tension. The resonating length of the wire with fundamental frequency of $$600 \mathrm{~Hz}$$ under same tension _______ $$\mathrm{cm}$$.

In a single slit experiment, a parallel beam of green light of wavelength $$550 \mathrm{~nm}$$ passes through a slit of width $$0.20 \mathrm{~mm}$$. The transmitted light is collected on a screen $$100 \mathrm{~cm}$$ away. The distance of first order minima from the central maximum will be $$x \times 10^{-5} \mathrm{~m}$$. The value of $$x$$ is :