Question 1. Why the dipole moment of chloro benzene is shorter than cyclohexyl chloride?
Answer. Since the dipole moment is the cumulative affect and in charge and distance between the poles and in cyclohexyl chloride the bond length is larger than the bond length in chlorobenzene due to the partial double bond character between C-Cl bond and charge on (polarity) of C-Cl bond of cyclohexyl chloride is more than that of an chlorobenzene because of resonance.
In other words we can say that, the magnitude 9f negative and positive charge on chlorine and carbon respectively are less because of resonance and due to the partial bond character between C-Cl bond in chlorobenzene it's dipole moment is less than cyclohexyl chloride.
Question 2. The C-Cl bond length in chlorobenzene is shorter than (methyl-chloride) CH3Cl.
Answer. Due to the partial bond character between C-Cl bond in chlorobenzene the bond length of C-Cl bond is shorter than CH3Cl.
Question 3. Why does chloromethane have more dipole moment then chloromethane even after fluorine is more electronegative than chlorine?
Answer. The bond length of C-Cl bond is more than C-F and we know that dipole moment of any dipole depend upon charge and distance between dipole rather than only upon the charge that's why chloromethane have more dipole moment then fluoromethane.