A sheet of plywoo

The shadow will not be formed in each case.

1. The muslin cloth will form the shadow but it will be lighter because muslin cloth is translucent due to which light will partially pass through it.

2. The transparent glass will not form the shadow because for formation of the shadow the object should be opaque because opaque objects do not allow light to pass through them, they obstructs the path of the light.

3. The sheet of plywood will form the perfect dark shadow because it is opaque hence it will obstruct all the light falling on it.