Question

A ceiling fan having M.I.2kgm² attains max.frequency of 60r.p.m.in2 second calculate it's power rating

Answer 1

Answer:

Power rating of fan = 40 W

Explanation:

Moment of Inertia I = 2 kg m²

As fan starts from rest and attains max frequency

Initial angular velo ω₀ = 0

Final angular velo  ω = 2πN/60 = 2π x 60/60 = 2π rad /s

Angular accln α = (ω - ω₀) / t = 2π/2 = π rad/s²

Maximum Torque τ = I α = 2 x π = 2π N m

Power rating = Pmax = Torque x angular velo

                                   = τω

                                   = 2π x 2π

                                   = 4 x π²

                                   = 4 x 3.14 x 3.14

                                   = 39.43

                                   = 40 W

Answer 2

Answer:

power rating of fan is 40W