Difficulty: Easy
Correct Answer: Wear wool clothing at all times.
Explanation:
Introduction / Context:
CMOS inputs are susceptible to electrostatic discharge. Proper ESD practice prevents latent or immediate device damage. Some habits reduce charge buildup; others make it worse.
Given Data / Assumptions:
Concept / Approach:
Best practice includes working on grounded surfaces, using wrist straps, keeping humidity reasonable, and never hot-plugging unprotected CMOS. Insulative clothing and carpets increase ESD risk and are discouraged.
Step-by-Step Solution:
Identify clearly bad advice: wearing wool promotes static.Other listed items match standard ESD guidelines (ground everything, power off before insertion).
Verification / Alternative check:
ESD control manuals recommend conductive mats, wrist straps, and avoiding static-generating materials like wool or some synthetics.
Why Other Options Are Wrong:
Grounding surfaces and tools reduces ESD risk.Pins-down on grounded surface equalizes potential.Inserting with power off avoids latch-up and transients.
Common Pitfalls:
Forgetting that humidity affects ESD, and neglecting personal grounding measures when moving around the lab.
Final Answer:
Wear wool clothing at all times.
Discussion & Comments