Total number of cyclic isomers (excluding bicyclo and spiro) possible with the formula, C₄H₆ is

Number of alkynes = 2 ;

Number of terminal alkynes = 1 ;

Number of non terminal (internal) alkynes = 1 ;

Number of alkadienes = 2 ;

Number of cumulative dienes = 1 ;

Number of conjugated dienes = 1 ;

Number of acyclic isomers = 4 ;

Number of cycloalkenes = 4 ;

Number of cyclic isomers = 4 ;

Number of acyclic structural isomers = 4 ;

Number of acyclic stereo isomers = 0 ;

Number of cyclic structural isomers = 4 ;

Number of cyclic stereo isomers = 0 ;

Total number of  structural isomers = 8 ;

Total number of  stereo isomers = 0 ;

Total number of isomers = 8 ;