Electromagnetic induction principle discovered by: MCQ with Answer and Explanation

Explanation:
In Simple Harmonic Motion (like a swinging pendulum), velocity is maximum when the particle passes through its equilibrium or mean position. Since Kinetic Energy = ½mv², KE is maximum at the mean position. At the extreme positions, the velocity is briefly zero, meaning kinetic energy is zero and potential energy is maximum.

Explanation:
For low Earth orbit (r ≈ R_earth), orbital period T = 2π√(r³/GM). Using g = GM/R², T = 2π√(R/g). With R = 6.4×10⁶ m, g = 9.8 m/s², T ≈ 2×3.14×√(6.4e6/9.8) ≈ 6.28×√(653061) ≈ 6.28×808 ≈ 5076 s ≈ 84.6 minutes. Memory aid: 'Low orbit period ≈ 84 min; geostationary = 24 hours'. This standard result is frequently tested in competitive exams. Always recall that period increases with orbital radius; competitive exams often compare low orbit vs geostationary periods.

Explanation:
SI unit Newton (kg m/s²), CGS unit dyne (g cm/s²). 1 N = 10⁵ dyne. Conversion: 1 kg = 10³ g, 1 m = 100 cm, so 1 N = 10³ × 10² = 10⁵ dyne. Ratio N/dyne = 10⁵.