$A$ progressive wave of frequency $50 ~Hz$ is travelling with velocity $350 ~m/s$ through a medium. The change in phase at a given time interval of $0.01 ~s$ is

Consider the following reaction: $N_{2(g)} + 3H_{2(g)} \longrightarrow 2NH_{3(g)}$. The rate of this reaction in terms of $N_2$ at $T \ K$ is $-\frac{d[N_2]}{dt} = 0.02 \ mol \ L^{-1} \ s^{-1}$. What is the value of $-\frac{d[H_2]}{dt}$ (in units of $mol \ L^{-1} \ s^{-1}$) at the same temperature?

Which of the following equations represents a circle?

The middle lamella of a plant cell is primarily composed of which of the following?

If $A$ is a $3 \times 4$ matrix and $B$ is a matrix such that $A'B$ and $BA'$ are both defined,then $B$ is of the type: