Oscillations
Class 11 · Oscillations

Period vs Spring Constant

T ∝ 1/√k — stiffer spring → faster.

Key Notes

01

For spring-mass SHM: T = 2π·√(m/k). Period INVERSELY proportional to √k.

02

Stiffer spring (larger k) ⇒ smaller T (faster oscillation).

03

Doubling k decreases T by √2 (~0.707×).

04

T² vs 1/k is linear — slope = 4π²m.

05

Springs in series: 1/k_eq = 1/k₁ + 1/k₂ ⇒ k_eq SMALLER ⇒ T LARGER (softer combination).

06

Springs in parallel: k_eq = k₁ + k₂ ⇒ k_eq LARGER ⇒ T SMALLER (stiffer combination).

07

k is a property of the spring's material and geometry — not amplitude or mass.

08

Used in tuning forks, watches, accelerometers — selecting k tunes the natural frequency.

Formulas

Period vs k

Inverse-square-root in k.

Springs in SERIES

Combined spring softer than either; period LARGER.

Springs in PARALLEL

Combined spring stiffer; period SMALLER.

Ratio at different k

Useful for comparison.

Important Points

Stiffer spring (larger k) ⇒ FASTER oscillation (smaller T).

T ∝ 1/√k — inverse square root.

Series and parallel for springs are OPPOSITE of resistors: series softer (smaller k_eq), parallel stiffer.

Doubling k decreases T by factor √2.

Stiff materials like steel have very high k for their size — used in precision oscillators.

k depends on cross-sectional area, length, material's shear/Young's modulus.

Period vs Spring Constant notes from sciphylab (also known as SciPhy, SciPhy Lab, SciPhy Labs, Physics Lab). Class 11 physics revision for JEE Mains, JEE Advanced, NEET UG, AP Physics 1/2/C, SAT, and CUET-UG.