Which of the following is the strongest oxidizing agent?

$A$ source of sound is travelling with a velocity of $40\, km/h$ towards an observer and emits sound of frequency $2000\, Hz$. If the velocity of sound is $1220\, km/h$,what is the apparent frequency heard by the observer in $Hz$?

Plants which are attached to the rocks are called

The first biosphere reserve established in India for conserving the gene pool of flora and fauna and the lifestyle of tribals is

If $\frac{1 - \cos x}{\cos x(1 + \cos x)} = \frac{\sin \alpha}{\cos x} - \frac{2}{1 + \cos x}$,then $\alpha = $

With respect to chlorobenzene,which of the following statements is not correct?