Which standard uses 50 Hz fields per second for analog color television?

Which standard uses 50 Hz fields per second for analog color television?

• A. NTSC
• B. PAL
• C. OMF
• D. Optical Sound

Answer: (C)

The concept here is how interlaced analog color TV delivers video in two alternating fields and how often those fields appear. In analog color systems, each frame is split into two fields that alternate, so the field rate determines the visible refresh. PAL runs at a 50 Hz field rate: there are 25 frames per second, and each frame has two interlaced fields, giving 50 fields each second. NTSC runs at about 60 Hz fields per second (approximately 59.94), not 50. The other options aren’t broadcast standards for video fields—OMF is a post‑production interchange format, and Optical Sound is sound-on-film. So the standard that uses 50 Hz fields per second is PAL.

The concept here is how interlaced analog color TV delivers video in two alternating fields and how often those fields appear. In analog color systems, each frame is split into two fields that alternate, so the field rate determines the visible refresh. PAL runs at a 50 Hz field rate: there are 25 frames per second, and each frame has two interlaced fields, giving 50 fields each second. NTSC runs at about 60 Hz fields per second (approximately 59.94), not 50. The other options aren’t broadcast standards for video fields—OMF is a post‑production interchange format, and Optical Sound is sound-on-film. So the standard that uses 50 Hz fields per second is PAL.