Which of the following is an amphoteric oxide?

If ${N_a} = \{ an : n \in N \}$,then ${N_3} \cap {N_4} = $

An electron collides with an atom in its ground state at rest. The atom then emits a photon of energy $E_{photon}$. In this process,the change $\Delta E_{elec}$ in the electron's energy is

If the volume of a block of metal changes by $0.12 \%$ when it is heated through $20 ^oC$, the coefficient of linear expansion (in $^oC^{-1}$) of the metal is

$A$ body executes simple harmonic motion under the action of a force $F_1$ with a time period $(4/5) \ s$. If the force is changed to $F_2$,it executes $SHM$ with a time period $(3/5) \ s$. If both the forces $F_1$ and $F_2$ act simultaneously in the same direction on the body,its time period (in $seconds$) is

$A$ conducting rod of length $L$ rotates with angular speed $\omega$ in a uniform magnetic field of induction $B$ which is perpendicular to its motion. The induced emf developed between the two ends of the rod is