Physics Formula Notes for Competitive Exams
1. Mechanics & Motion
Mechanics is the most frequently asked topic in competitive exams. Ensure you remember the kinematic equations and Newton’s laws.
| Concept | Formula |
|---|---|
| Velocity | v = s / t |
| Acceleration | a = (v - u) / t |
| Force | F = m × a |
| Work | W = F × d × cos(θ) |
Kinematic Equations of Motion:
- v = u + at
- s = ut + ½at²
- v² = u² + 2as
2. Heat & Thermodynamics
Temperature Conversion Formulas:
Often asked in SSC exams, these conversion formulas are critical:
- Celsius to Kelvin: K = °C + 273.15
- Celsius to Fahrenheit: °F = (°C × 9/5) + 32
3. Optics & Light
Mirror and Lens formulas are evergreen topics for competitive physics.
Mirror Formula: 1/f = 1/v + 1/u
Lens Formula: 1/f = 1/v - 1/u
Magnification (m): m = h'/h = -v/u (for mirrors) or v/u (for lenses)
4. Electricity & Magnetism
| Concept | Formula | Unit |
|---|---|---|
| Ohm's Law | V = I × R | Volts |
| Power | P = V × I = I²R | Watt |
| Resistance in Series | R = R₁ + R₂ + ... | Ohm (Ω) |
Most Important Points Summary
- Newton’s Second Law: Force is the product of mass and acceleration (F=ma).
- Work Done: Zero work is done if the force is perpendicular to the displacement.
- Ohm’s Law: Current is directly proportional to voltage at a constant temperature.
- Kinetic Energy: KE = ½mv².
- Potential Energy: PE = mgh.
Frequently Asked Questions (FAQs)
Q1: What is the SI unit of power?
A: The SI unit of power is Watt (W).
Q2: Define the mirror formula?
A: The mirror formula is 1/f = 1/v + 1/u, where 'f' is focal length, 'v' is image distance, and 'u' is object distance.
Q3: How is kinetic energy related to momentum?
A: KE = p²/2m, where 'p' is momentum and 'm' is mass.
Q4: What is the value of gravitational constant (G)?
A: G ≈ 6.674 × 10⁻¹¹ N·m²/kg².
Q5: Which formula determines the heat produced in a resistor?
A: Joule’s Law of Heating: H = I²Rt.
Conclusion
Mastering these Physics Formula Notes will provide you a strong foundation for any competitive examination. Focus on practicing numericals based on these formulas to ensure high scores in the science section.
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