CONCEPT:The ripple frequency of a half-wave RECTIFIER is f0, where f0 is the INPUT line frequency.The ripple frequency of a center-tapped or a bridge-type full-wave rectifier is 2f0.Analysis:Given f0 = 50 Hz.∴ The Ripple frequency (HWR) will be 50 Hz. (Option (1) is correct)And the Ripple frequency of a full-wave rectifier will be 100 Hz. (Option 2 is incorrect and 3 is correct)