A logic family shows the following values:VOH = 5 V, VOL = 1 V, VIH = 3 V, and VIL = 2 V.The noise margins, NMhigh and NMlow, respectively, will be:

Explanation:

Concept:In a digital circuit, the Noise Margin is the amount by which the signal exceeds the threshold for a proper ‘0’ or ‘1’.For Ex: a Digital circuit might be designed to swing between 0 and 1.2 Volts, with anything below 0.2 V considered as a ‘0’ and anything above 1 Volt is considered a ‘1’. Then the noise margin for a ‘0’ would be the amount that a signal is below 0.2 Volts, and a noise margin for 1 would be the amount by which a signal exceeds 1 Volt.In this case noise margins are measured as an absolute voltage, not as a ratio.This is schematically explained with the help of the following diagram:NMlow = VIL – VOLNMhigh = VOH - VIHCalculation:Given voltage levels are VIL = 2 V VOL = 1 V, VOH = 5 V, VIH = 3 VNMlow = VIL – VOL = 2 V – 1 VNMlow = 1 VNMhigh = VOH - VIH = 5 V – 3 VNMhigh = 2 VSo option(1) is the CORRECT ANSWER.