In the following combinations of logic gates,the outputs $A, B$ and $C$ are respectively

At any instant,two elements $X_1$ and $X_2$ have the same number of radioactive atoms. If the decay constants of $X_1$ and $X_2$ are $10 \lambda$ and $\lambda$ respectively,then the time when the ratio of their atoms becomes $\frac{1}{e}$ will be:

The following band-energy diagram represents:

Which one of the following statements is incorrect about menstruation?

Ammonia can be dried by

The ends of a stretched wire of length $L$ are fixed at $x = 0$ and $x = L$. In one experiment,the displacement of the wire is $y_1 = A \sin(\pi x/L) \sin(\omega t)$ and the energy is $E_1$. In another experiment,its displacement is $y_2 = A \sin(2\pi x/L) \sin(2\omega t)$ and the energy is $E_2$. Then: