Modern Physics ...

The plate resistance of a triode is 3 × 10³ ohms and its mutual conductance is 1.5 × 10^–3 amp/volt. The amplification factor of the triode is

The half life of radioactive Radon is 3.8 days. The time at the end of which 1/20 th of the radon sample will remainundecayed is (given log₁₀ e = 0.4343)

An alpha particle of energy 5 MeV is scattered through 180° by a fixed uranium nucleus. The distance of closest approach is of the order of

Beta rays emitted by a radioactive material are

If elements with principal quantum number n > 4 were not allowed in nature, the  number of possible elements would be

Consider the spectral line resulting from the  transition n = 2 → n = 1 in the atoms and ions given below. The shortest wavelength is produced by

The equation  represents

Fast neutrons can easily be slowed down by

Consider α particles, β particles and γ - rays, each having an energy of 0.5 MeV. In increasing order of penetrating powers, the radiations are:

An energy of 24.6 eV is required to remove one of the electrons from a neutral helium atom. The energy in (eV) required to remove both the electrons from a neutral helium atom is