🔥 Mechanics
| Quantity |
Formula |
Mnemonic |
| Force |
F = ma |
“F=Ma” sounds like “Effort = Move it!” |
| Momentum |
p = mv |
“p” for push |
| Work |
W = F·s·cosθ |
Work = Force slides |
| Power |
P = W/t |
Power is Work time |
| Kinetic Energy |
KE = ½mv² |
“Half-em-vee-square” |
| Potential Energy |
PE = mgh |
“Em-G-H” = Mountain-Gravity-Height |
🌊 Fluids & Thermo
- Density: ρ = m/V → “Rho = Mass per Volume”
- Pressure: P = F/A → “Press = Force over Area”
- Buoyant Force: F = ρgV → “Rho-g-V lifts you up”
- Ideal Gas: PV = nRT → PeVe NeRaTa (Hindi: Pee-Vee-Nerat)
- Heat: Q = mcΔT → “Q = mc-Delta-T” like McDonald’s ΔT burger
⚡ Electricity & Magnetism
| Name |
Formula |
Trick |
| Ohm’s Law |
V = IR |
“Very Impolite Rascal” |
| Power (elec) |
P = VI = I²R = V²/R |
“Play Virtual India” |
| Resistance (series) |
R_eq = R₁ + R₂ + … |
“Sum up” |
| Resistance (parallel) |
1/R_eq = 1/R₁ + 1/R₂ |
“Flip & add” |
| Force on charge |
F = qvB sinθ |
“Fast queen van Bends” |
🌌 Waves & Light
- Wave speed: v = fλ → “Very fast λambda”
- Lens formula: 1/f = 1/v + 1/u → “Friend Visits U”
- Refractive index: n = c/v → “n is c over v”
- Snell’s Law: n₁sinθ₁ = n₂sinθ₂ → “N1-S1 = N2-S2”
🚀 Motion in 1-D
- v = u + at
- s = ut + ½at²
- v² = u² + 2as
- Mnemonic: “Unique Attitude Takes Success”
🧲 Magnetic Field
- Straight wire: B = μ₀I/(2πr) → “Mu-Zero-I-over-2-Pi-r”
- Solenoid: B = μ₀nI → “n turns give Boost”
🎯 10 Rapid-Fire MCQs
1. A 2 kg mass accelerates at 4 m/s². Force is?
**Ans:** 8 N (F = ma = 2×4)
2. Power = 100 W, time = 5 s. Work done?
**Ans:** 500 J (W = P×t)
3. KE of 4 kg mass at 10 m/s?
**Ans:** 200 J (½×4×10²)
4. 3 resistors 2 Ω each in series. R_eq?
**Ans:** 6 Ω
5. Same 3 resistors in parallel. R_eq?
**Ans:** 2/3 Ω
6. Frequency 50 Hz, λ = 4 m. Wave speed?
**Ans:** 200 m/s (v = fλ)
7. A lens has f = 20 cm, u = 30 cm. v is?
**Ans:** 60 cm (1/v = 1/f – 1/u)
8. Q = 2 kg copper, c = 0.4 J/g°C, ΔT = 50°C. Q in kJ?
**Ans:** 40 kJ (Q = mcΔT = 2000×0.4×50)
9. Current 2 A, resistance 5 Ω. Power?
**Ans:** 20 W (P = I²R)
10. A body falls freely from rest for 5 s (g = 10 m/s²). Distance?
**Ans:** 125 m (s = ½gt²)
Last-minute tip: Write formulas on 3×3 sticky notes—stick on your mirror; glance twice daily → Retained till exam day!
BETA
