When the dust cup is not attached to a vacuum cleaner, the machine will not effectively pick up dirt and debris as it normally would. The dust cup is an essential part of the vacuum cleaner's design, as it serves as a container to collect the dirt, dust, and debris that the vacuum sucks up from the floor or surfaces.
Without the dust cup, there is no place for the dirt and debris to accumulate, and as a result, the vacuum cleaner will simply expel the collected material back into the environment. The vacuum's suction may still move some loose debris around, but it won't be effectively removed from the floor or surfaces you are trying to clean.
To ensure proper functioning and optimal cleaning performance, always make sure the dust cup is securely attached to your vacuum cleaner before using it. Additionally, remember to empty the dust cup regularly to prevent it from becoming too full and decreasing the vacuum's efficiency.