The degree of ionization of $0.10 \ M$ lactic acid is $4.0 \ \%$. The value of $K_a$ is

$A$ gamma ray photon creates an electron-positron pair. If the rest mass energy of an electron is $0.5 \, MeV$ and the total $K.E.$ of the electron-positron pair is $0.78 \, MeV$,then the energy of the gamma ray photon must be .......... $MeV$.

$100 \ mL$ of $0.6 \ M$ acetic acid is shaken with $2 \ g$ of activated charcoal. After adsorption,the final concentration of the solution becomes $0.5 \ M$. The amount of acetic acid adsorbed per gram of carbon is .......... $g$.

The basis of the quantum mechanical model of an atom is

The relation between the coefficient of real expansion $(\gamma_r)$ and coefficient of apparent expansion $(\gamma_a)$ of a liquid and the coefficient of linear expansion $(\alpha_g)$ of the material of the container is

An aluminium ring $B$ faces an electromagnet $A$. The current $I$ through $A$ can be altered. Which of the following statements is correct?