How soon after passing the examination for your first amateur radio license may you transmit on the amateur radio bands?
Immediately on receiving your Certificate of Successful Completion of Examination (CSCE)
As soon as your operator/station license grant appears on the ARRL website
As soon as your operator/station license grant appears in the FCC’s license database✓Bonne réponse
As soon as you receive your license in the mail from the FCC
Explication
You may not transmit until the FCC has actually granted the license and it shows in the ULS database. Passing the exam and holding a CSCE gives you no transmitting authority of its own, and no paper license arrives in the mail.