Modern Physics ...

A radioactive sample consists of two distinct species having equal number of atoms initially. The mean life time of one species is τ and that of the other is 5τ. The decay products in both cases are stable. A plot is made of the total number of radioactive nuclei as a function of time. Which of the following figures best represent the form of this plot?

The potential difference applied to an X-ray tube is 5kV and the current through it is 3.2mA. Then the number of electrons striking the target per second is

A Hydrogen atom and a Li⁺⁺ ion are both in the second excited state. If ℓ _H and ℓ _Li are their respective electronic angular momenta, and E_H and E_Li their respective energies, then

The half-life of ²¹⁵At is 100 μ s. The time taken for the radioactivity of a sample of ²¹⁵At to decay to 1/16^th of  its initial value is

Which of the following processes represents a γ -decay ?

The electric potential between a proton and an electron is given by  where r₀ is a constant. AssumingBohr’s model to be applicable, write variation of r_n with n, n being the principal quantum number?

If the atom ₁₀₀Fm²⁵⁷ follows the Bohr model and the radius of ₁₀₀Fm²⁵⁷ is n times the Bohr radius, then find n.

For uranium nucleus how does its mass vary with volume?

A nucleus with mass number 220 initially at rest emits an α -particle. If the Q value of the reaction is 5.5 MeV, calculate the kinetic energy of the α -particle

In a photoelectric experiment anode potential is plotted against plate current.