We are given with a compound (X) having molecular formula C4H7Cl. Find out number of its cyclic isomers (structural and geometrical only) (excluding optical isomers).

To find the number of cyclic isomers for the given compound (X) with molecular formula C4H7Cl, we need to understand the structure of the compound.

1. First, let's determine the degree of unsaturation in the compound. The formula for degree of unsaturation is (2n+2) - H, where n is the number of carbon atoms. For our compound, n=4. So, the degree of unsaturation is (2*4+2) - 7 = 1. This means our compound has one ring or one double bond.

2. Since we are looking for cyclic isomers, we can assume that the degree of unsaturation is due to a ring.

3. Now, let's draw the possible structures. We have 4 carbon atoms and 1 chlorine atom. The chlorine atom can be attached to any of the carbon atoms in the ring.

4. The possible cyclic isomers are:

   • A three-membered ring with one methyl group and one chlorine atom.
   • A four-membered ring with one chlorine atom.

5. However, we also need to consider the geometrical isomers. Geometrical isomers occur due to restricted rotation around a double bond or a ring. But in our case, there are no geometrical isomers because there are no substituents on the ring that can lead to cis-trans isomerism.

So, the total number of cyclic isomers (structural and geometrical) for the compound (X) with molecular formula C4H7Cl is 2.