| Pattern | Frequency | Years | Trap | How to Avoid |
|---|---|---|---|---|
| Dimensional formula identification | High (1–2 Qs every 2–3 years) | 2019, 2021, 2022 | Confusing [M^{1}$$L^{-1}$$T^{-2}] options: pressure, stress, energy density all share same formula | Memorise exactly 5 quantities with [M^{1}$$L^{-1}$$T^{-2}]: pressure, stress, Young's modulus, bulk modulus, energy density |
| Percentage error in derived formula | High (almost every year) | 2017, 2018, 2020, 2023 | Forgetting to multiply % error by the power of the variable | Write formula, identify each variable's power, then apply: total% = Σ(power × individual%) |
| Significant figures counting | Moderate | 2016, 2019, 2022 | Numbers like 0.0046 (2 sig figs) vs 1.500 (4 sig figs) | "Leading zeros: 0 sig figs; trailing zeros after decimal: count them" |
| Unit conversion using dimensional method | Moderate | 2018, 2021 | Forgetting to apply conversion for all base units (e.g., only converting mass but not length) | Always write all three: (/)ᵃ × (/)ᵇ × (/)ᶜ |
| Limitation of dimensional analysis | Low-Moderate | 2015, 2020 | Thinking dimensional correctness confirms physical correctness | "DA cannot find constants; DA cannot distinguish same-dimension formulas" |
| Systematic vs random error MCQ | Low | 2016, 2022 | Claiming systematic errors can never be corrected | Systematic errors CAN be corrected by recalibration; random errors can only be reduced by averaging |
Top NEET Traps for ME-01:
- Subtracting errors in Z = A/B (correct answer: add relative errors)
- Leading zeros counted as significant
- Thinking dimensional analysis can confirm the 1/2 in KE = 1/2
- Applying decimal-place rule to multiplication instead of sig-fig rule