A bicycle wheel of radius ' R ' has ' n ' spokes. It is rotating at the rate of ' F ' r.p.m. perpendicular to the horizontal component of earth's magnetic field B. The e.m.f. induced between the rim and the centre of the wheel is (a) 1/2Bπ FR² (b) Bπ FR² (c) 1/nBπ FR (d) Bπ FR² n

Answer: (b). Each spoke is a rod of length R rotating about one end: e = 1/2Bω R². Spokes are in parallel, so n does not matter. With ω = 2π F: e = 1/2B(2π F)R² = Bπ FR² So the answer is (b) Bπ FR².

A bicycle wheel of radius ' R ' has ' n ' spokes. It is rotating at… | MHT CET 2024 (2 May, Shift 1)

Q14MHT CET 2024 · 2 MAY · SHIFT 1Medium

Rotating Conductors & AC Generator

A bicycle wheel of radius ' $R$ ' has ' $n$ ' spokes. It is rotating at the rate of ' $F$ ' r.p.m. perpendicular to the horizontal component of earth's magnetic field $\vec{B}$ . The e.m.f. induced between the rim and the centre of the wheel is

Show answer and solution

Answer: (b)

Each spoke is a rod of length $R$ rotating about one end: $e = \frac{1}{2}B\omega R^2$ . Spokes are in parallel, so $n$ does not matter.
With $\omega = 2\pi F$ : $e = \frac{1}{2}B(2\pi F)R^2 = B\pi FR^2$
So the answer is (b) $B\pi FR^2$ .

Report a mistake

Rotating Conductors & AC Generator question from MHT CET 2024 (2 May, Shift 1)

More questions on Rotating Conductors & AC Generator