Resistor categories with tolerance ratings of ±5% or greater are generally referred to as which class?
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Aprecision
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BSIP
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Cgeneral-purpose
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Dwirewound
Answer
Correct Answer: general-purpose
Explanation
Introduction / Context:Resistors are grouped by tolerance classes that indicate expected deviation from nominal value. Designers choose precision parts for tight control and general-purpose parts where wider variation is acceptable at lower cost.
Given Data / Assumptions:
- Tolerance threshold of about ±5% or larger.
- Standard commodity resistors used in many noncritical applications.
Concept / Approach:Precision resistors typically have tolerances tighter than ±1% (e.g., ±0.1% to ±1%). General-purpose resistors commonly have ±5% or ±10% tolerances, adequate for pull-ups, biasing, and general signal routing. Tolerance class impacts error budgets and matching performance.
Step-by-Step Solution:Identify tolerance: ≥ ±5% falls outside the precision category.Map to class: commodity carbon film or thick-film parts are generally classified as general-purpose.Therefore, the correct classification is general-purpose.
Verification / Alternative check:Distributor catalogs categorize ±1% and tighter as precision; ±5% and ±10% are listed as general-purpose, confirming the terminology used in practice.
Why Other Options Are Wrong:
- Precision: Reserved for ±1% or better (sometimes ±2%).
- SIP: Refers to a package style, not tolerance class.
- Wirewound: A construction type that can be either precision or power-rated; tolerance is not implied solely by being wirewound.
Common Pitfalls:
- Assuming construction type determines tolerance; process control and trimming dominate tolerance.
- Confusing package style with tolerance classification.
Final Answer:general-purpose