The angular momentum for the electron in Bohr's orbit is L. If the electron is assumed to revolve in second orbit of hydrogen atom, then the change in angular momentum will be

A radio active material is reduced to $$1 / 8$$ of its original amount in 3 days. If $$8 \times 10^{-3} \mathrm{~kg}$$ of the material is left after 5 days the initial amount of the material is

The waves emitted when a metal target is bombarded with high energy electrons are

For a nucleus $${ }_{\mathrm{A}}^{\mathrm{A}} \mathrm{X}$$ having mass number $$\mathrm{A}$$ and atomic number $$\mathrm{Z}$$

A. The surface energy per nucleon $$\left(b_{\mathrm{s}}\right)=-a_{1} A^{2 / 3}$$.

B. The Coulomb contribution to the binding energy $$\mathrm{b}_{\mathrm{c}}=-a_{2} \frac{Z(Z-1)}{A^{4 / 3}}$$

C. The volume energy $$\mathrm{b}_{\mathrm{v}}=a_{3} A$$

D. Decrease in the binding energy is proportional to surface area.

E. While estimating the surface energy, it is assumed that each nucleon interacts with 12 nucleons. ( $$a_{1}, a_{2}$$ and $$a_{3}$$ are constants)

Choose the most appropriate answer from the options given below: