The reaction of benzene diazonium chloride with $Cu$ powder and $HCl$ is known as:

The Ullmann reaction is used for the preparation of .......

Identify the major product formed when $p$-isopropyltoluene (also known as $p$-cymene) reacts with a mixture of concentrated $HNO_3$ and concentrated $H_2SO_4$.

Among the following,the reaction that proceeds through an electrophilic substitution is

The decreasing order of reactivity of the given compounds towards nucleophilic substitution with aqueous $NaOH$ is:
$(I)$ $1$-bromo-$3$-nitrobenzene
$(II)$ $1$-bromo-$2,4,6$-trinitrobenzene
$(III)$ $1$-bromo-$4$-nitrobenzene
$(IV)$ $1$-bromo-$2,4$-dinitrobenzene

Which of the following reactions yields biphenyl from chlorobenzene?