Final answer:
The House Rules Committee is the extremely powerful congressional committee that determines when debate on a bill will take place.
Step-by-step explanation:
The extremely powerful congressional committee that determines when debate on a bill will take place is the House Rules Committee.
This committee is responsible for setting the rules and procedures for how bills will be debated and amended on the floor of the House of Representatives. They can determine the amount of time for debate, which amendments can be considered, and other important aspects of the legislative process.