The expression `(me^(4))/(8 varepsilon_(0)^(2)h^(3)c)` has the dimension (m= mass,e= electric charge,`varepsilon_(0)`=permittivity,h=planck's constant and c= velocity of light `L^(x)`.Find X.

The parameter (mQ^(4))/(epsilon_(0)^(2)h^(2)) has the dimensions of ( m = mass Q = charge in_(0) = Permittivity and h = Planck's constant )

The dimensions of e^(2)//4pi epsilon_(0)hc , where e, epsilon_(0),h and c are electronic charge, electric permittivity, Planck’s constant and velocity of light in vacuum respectively

The dimension of the quantity 1/epsilon_0 e^2/(hc) is (e charge of electron,h Planck's constant and c=velocity of light)

Dimensional formula of (e^(4))/(epsilon_(0)^(2)m_(p)m_(e)^(2)c^(3)G) is (Where e= charge , m_(p) and m_(c ) are masses, epsilon_(0)= permittivity of free space, c= velocity of light and G= gravitational constant)

(he)/(4 pi m) has the same dimensions as (h = Planck's constant , e = charge , m = mass.)

epsilon_(0)E^(2) has the dimensions of ( epsilon_(0)= permittivity of free space, E= electric field) Here k= Boltzmann consant T= absolute temperature R= universal gas constant.

The positron is a fundamental particle with the same mass as that of the electron and with a charge equal to that of an electron but of opposite sign. When a positron and an electron collide, they may annihilate each other. The energy corresponding to their mass appears in two photons of equal energy. Find the wavelength of the radiation emitted. [Take : mass of electron = (0.5//c^(2))MeV and hc = 1.2 xx 10^(-12) MeV-m , where h is the Planck's constant and c is the velocity of light in air.

When a metal surface is illuminated by light wavelengths 400 nm and 250 nm , the maximum velocities of the photoelectrons ejected are upsilon and 2 v respectively . The work function of the metal is ( h = "Planck's constant" , c = "velocity of light in air" )

Let [varepsilon_0] denote the dimensional formula of the permittivity of vacuum. If M =mass , L=length, T=time and I= electric current Then

Let E=(-1me^(4))/(8epsilon_(0)^(2)n^(2)h^(2)) be the energy of the n^(th) level of H-atom state and radiation of frequency (E_(2)-E_(1))//h falls on it ,