The audible range of sound for human beings is MCQ with Answer and Explanation

Explanation:
T = 2π√(L/g). For small amplitudes, period independent of amplitude and mass. Depends only on effective length and acceleration due to gravity. Used in pendulum clocks.

Explanation:
Iris adjusts pupil size. In bright light pupil constricts, dim light dilates. Retina forms image. Cornea and lens focus. Eye is like camera.

Explanation:
By conservation of angular momentum: I1w1 = I2w2. Moment of inertia of a solid sphere is 2/5 MR^2. So, (R1^2) * (2pi/T1) = (R2^2) * (2pi/T2). If radius halves, R2 = R1/2. R1^2 / T1 = (R1/2)^2 / T2. T2 = T1 / 4. A day is 24 hours, so 24/4 = exactly 6 hours.