Correct AnswerB. a resistor and capacitor
Quick Explanation
For a nonretriggerable one-shot, once triggered the output pulse lasts for the timing interval determined by its external timing components. Additional triggers arriving during that interval do not restart or extend the pulse. Therefore the pulse-width dependence specified by option B is correct.
Detailed Explanation
Correct Answer
B — a resistor and capacitor
Concept and Reasoning
For a nonretriggerable one-shot, once triggered the output pulse lasts for the timing interval determined by its external timing components. Additional triggers arriving during that interval do not restart or extend the pulse. Therefore the pulse-width dependence specified by option B is correct.
Calculation / Key Relation
Typical one-shot width T≈kRC (device dependent)
Exam Takeaway
Nonretriggerable: new trigger during the pulse is ignored.
Common Mistake
Do not confuse pulse width with trigger repetition period.
