A technical query (TQ) is a document containing a question or questions which is raised by the contractor to their client. It is a contractual document which requires a formal response from the client. A TQ is a method to clarify and resolve ambiguities in the contract or scope of work. In most cases, the parties will be able to agree into the resolution of the issue.
There are some instances, however, instead of resolving the issue raised, it will escalate into a larger issue due to the ambiguities in the contract or scope of work. This may be the worse case that could happen. Thus, if you are the contractor, raise a TQ only when you know what you are doing. If not, you may create more issues than what you are trying to solve. In this scenario, project delivery will be delayed to the annoyance of the client (and the contractor as well).