,📌 1. PHYSICAL QUANTITIES
A physical quantity is a measurable quantity expressed with a magnitude and a unit.
🔹 Types:
Fundamental Quantities: Length (L), Mass (M), Time (T), etc.
Derived Quantities: Velocity, Acceleration, Force
📌 2. SI UNITS (CORE CONCEPT)
Quantity SI Unit Symbol
Length meter m
Mass kilogram kg
Time second s
Current ampere A
Temperature kelvin K
Substance mole mol
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📌 3. DIMENSIONAL ANALYSIS (VERY HIGH WEIGHTAGE 🔥)
🔹 Standard Dimensional Formulas:
Velocity → [M⁰ L¹ T⁻¹]
Acceleration → [M⁰ L¹ T⁻²]
Force → [M¹ L¹ T⁻²]
Work → [M¹ L² T⁻²]
Pressure → [M¹ L⁻¹ T⁻²]
🔹 Applications:
✔ Check dimensional correctness
✔ Convert units
✔ Derive relations
, 📌 4. ERRORS IN MEASUREMENT
🔹 Types:
1. Systematic Errors → Instrument/calibration issues
2. Random Errors → Unpredictable
3. Least Count Errors
🔹 Important Formulas:
Absolute Error = |Measured − True|
Mean Absolute Error = (Σ Errors) / n
Percentage Error = (Absolute Error / True Value) × 100
📌 5. SIGNIFICANT FIGURES (SCORING + TRICKY)
🔹 Rules:
All non-zero digits → significant
Zeros between digits → significant
Leading zeros → not significant
Trailing zeros (decimal) → significant
🔹 Operations Rule:
Multiplication/Division → least significant figures
Addition/Subtraction → least decimal places
📌 6. ROUNDING OFF RULES
Digit < 5 → ignore
Digit ≥ 5 → increase previous digit
A physical quantity is a measurable quantity expressed with a magnitude and a unit.
🔹 Types:
Fundamental Quantities: Length (L), Mass (M), Time (T), etc.
Derived Quantities: Velocity, Acceleration, Force
📌 2. SI UNITS (CORE CONCEPT)
Quantity SI Unit Symbol
Length meter m
Mass kilogram kg
Time second s
Current ampere A
Temperature kelvin K
Substance mole mol
Luminous Intensity candela cd
📌 3. DIMENSIONAL ANALYSIS (VERY HIGH WEIGHTAGE 🔥)
🔹 Standard Dimensional Formulas:
Velocity → [M⁰ L¹ T⁻¹]
Acceleration → [M⁰ L¹ T⁻²]
Force → [M¹ L¹ T⁻²]
Work → [M¹ L² T⁻²]
Pressure → [M¹ L⁻¹ T⁻²]
🔹 Applications:
✔ Check dimensional correctness
✔ Convert units
✔ Derive relations
, 📌 4. ERRORS IN MEASUREMENT
🔹 Types:
1. Systematic Errors → Instrument/calibration issues
2. Random Errors → Unpredictable
3. Least Count Errors
🔹 Important Formulas:
Absolute Error = |Measured − True|
Mean Absolute Error = (Σ Errors) / n
Percentage Error = (Absolute Error / True Value) × 100
📌 5. SIGNIFICANT FIGURES (SCORING + TRICKY)
🔹 Rules:
All non-zero digits → significant
Zeros between digits → significant
Leading zeros → not significant
Trailing zeros (decimal) → significant
🔹 Operations Rule:
Multiplication/Division → least significant figures
Addition/Subtraction → least decimal places
📌 6. ROUNDING OFF RULES
Digit < 5 → ignore
Digit ≥ 5 → increase previous digit
