Ham Radio Extra Class Practice Test 2026 - Free Extra Class License Exam Questions and Study Guide

A fast-scan television frame, specifically referring to the NTSC (National Television System Committee) format, is composed of 525 horizontal scan lines. This structure allows for the display of a complete video image, as each frame is constructed by scanning these lines from top to bottom.

In the NTSC standard, the scanning process involves alternating between two fields, with each field consisting of 262.5 lines. Since these fields are interlaced, they combine to form the full frame of 525 lines. This interlacing helps to create smoother motion in video playback.

The other choices do not align with the NTSC standard. The number "30" does not represent any standard frame format, "60" refers to the number of fields per second in a 60 Hz refresh frequency, often correlated with the display rate of NTSC, while "1080" is characteristic of high-definition formats such as 1080p and does not apply to NTSC. Thus, the accurate number of lines making up an NTSC television frame is indeed 525.