Physics — Formula Sheet
Key formulas for TS Intermediate 2nd Year Physics — all 16 chapters as per the TGBIE Annual Plan 2025-26. Most-tested chapters shown with fuller formula sets. Paper: 60 marks · 3 hours.
1.
Waves
- v = fλ — wave speed, frequency, wavelength relationship
- T = 1/f — time period
- Doppler effect (source moving): f′ = f(v ± v_observer)/(v ∓ v_source)
- Standing wave: y = 2A sin(kx) cos(ωt)
- Fundamental frequency (string): f = (1/2L)√(T/μ)
- Beat frequency = |f₁ − f₂|
2.
Ray Optics & Optical Instruments
- Mirror formula: 1/f = 1/v + 1/u
- Magnification (mirror): m = −v/u = h′/h
- Snell's law: n₁ sin i = n₂ sin r; μ = sin i / sin r
- Lens formula: 1/f = 1/v − 1/u
- Lens maker's equation: 1/f = (n−1)[1/R₁ − 1/R₂]
- Prism: n = sin[(A+δₘ)/2] / sin(A/2)
- Microscope magnification: m = L/f_o × D/f_e
- Telescope magnification: m = f_o/f_e
3.
Wave Optics
- Young's double slit — fringe width: β = λD/d
- Path difference for bright fringe: Δ = nλ (n = 0, ±1, ±2, …)
- Path difference for dark fringe: Δ = (2n−1)λ/2
- Diffraction — first minimum: d sin θ = λ
- Brewster's angle: tan(θ_B) = n
4.
Electrostatics
- Coulomb's law: F = kq₁q₂/r² where k = 1/(4πε₀) = 9×10⁹ N m²/C²
- Electric field: E = F/q = kQ/r²
- Gauss's law: ∮ E·dA = q_enc/ε₀
- Electric potential: V = kQ/r; potential energy U = kq₁q₂/r
- Capacitance: C = Q/V; parallel plate: C = ε₀A/d
- Energy stored: U = ½CV² = Q²/2C
- Capacitors in series: 1/C = 1/C₁ + 1/C₂ + …
- Capacitors in parallel: C = C₁ + C₂ + …
6.
Current Electricity
- Ohm's law: V = IR; Resistivity: R = ρL/A
- Kirchhoff's laws: ΣI = 0 (junction), ΣV = 0 (loop)
- Wheatstone bridge balanced: P/Q = R/S
- Cells in series: E = E₁+E₂, r = r₁+r₂
- Cells in parallel: 1/r = 1/r₁+1/r₂; E_eff = (E₁/r₁+E₂/r₂)/(1/r₁+1/r₂)
- Potentiometer: E₁/E₂ = l₁/l₂
7.
Magnetic Effects of Current
- Biot-Savart law: dB = μ₀I dl sin θ / (4πr²)
- Field at centre of circular coil: B = μ₀nI / (2R)
- Straight wire: B = μ₀I / (2πr)
- Solenoid: B = μ₀nI (n = turns per unit length)
- Force on current: F = BIL sin θ
- Lorentz force: F = q(v × B)
- Radius in magnetic field: r = mv/(qB)
- Galvanometer to ammeter: S = Ig/(I−Ig) × G
9.
Electromagnetic Induction
- Faraday's law: ε = −dΦ/dt; Φ = B·A·cos θ
- Motional EMF: ε = Bvl
- Self-inductance: ε = −L(dI/dt); L for solenoid = μ₀n²Al
- Mutual inductance: ε₂ = −M(dI₁/dt)
10.
Alternating Current
- RMS values: V_rms = V₀/√2; I_rms = I₀/√2
- Inductive reactance: X_L = ωL; Capacitive reactance: X_C = 1/(ωC)
- Impedance: Z = √(R² + (X_L−X_C)²)
- Resonance: ω₀ = 1/√(LC); Q = ω₀L/R
- Power factor: cos φ = R/Z; P = V_rms I_rms cos φ
- Transformer: V₁/V₂ = N₁/N₂; I₁/I₂ = N₂/N₁
12.
Dual Nature of Radiation & Matter
- Photoelectric effect: hν = φ + (½mv²_max)
- Work function: φ = hν₀ (threshold frequency)
- de Broglie wavelength: λ = h/mv = h/p
- Energy of photon: E = hν = hc/λ
- Stopping potential: eV₀ = ½mv²_max
13.
Atoms & Nuclei
- Bohr: rₙ = n²a₀ (a₀ = 0.529 Å); Eₙ = −13.6/n² eV
- Transition energy: ΔE = E_higher − E_lower = hν
- Hydrogen spectra (Rydberg): 1/λ = R[1/n₁² − 1/n₂²]
- Mass-energy: E = mc²; Binding energy = Δm × 931.5 MeV/u
- Radioactive decay: N = N₀e^(−λt); T₁/₂ = 0.693/λ
- Activity: A = λN
15.
Semiconductor Electronics
- p-n junction: V₀ = barrier potential (~0.7 V for Si)
- Transistor: I_E = I_B + I_C; α = I_C/I_E; β = I_C/I_B
- β = α/(1−α); Voltage gain = β × R_C/R_B
- Rectifier: V_DC = V_m/π (half-wave); V_DC = 2V_m/π (full-wave)
- NAND: output = A̅·B̅; NOR: output = A̅+B̅