Clamp connection is found in

Nitrobenzene on reduction using zinc in alkaline medium results in $X$. The number of $\sigma$ and $\pi$ bonds in $X$ is

The wavelengths of light in two liquids '$x$' and '$y$' are $3500 \ \mathring A$ and $7000 \ \mathring A$ respectively. The critical angle of '$x$' with respect to '$y$' will be ...... $^o$.

Four successive members of the first series of the transition metals are listed below. For which one of them is the standard electrode potential $(E^o_{M^{2+}/M})$ value positive?

The five-kingdom classification system was proposed by whom?

Consider telecommunication through optical fibres. Which of the following statements is $NOT$ true?