A wheel with 20 metallic spokes each 1 m long is rotated with a speed of 120 rpm in a plane perpendicular to a magnetic field of 0.4 G. The induced emf between the axle and rim of the wheel will be, (1 G = 10-4 T)

Question

A wheel with 20 metallic spokes each 1 m long is rotated with a speed of 120 rpm in a plane perpendicular to a magnetic field of 0.4 G. The induced emf between the axle and rim of the wheel will be, (1 G = 10-4 T) (A) 2.51 × 10-4 V (B) 2.51 × 10-5 V (C) 4.0× 10-5 V (D) 2.51 V

Tardigrade Admin · Accepted Answer

ε=(1/2) B ω r2 ε=(1/2)×(0.4×10-4)×(2π[(120/60)])(1)2 ε=0.8π×10-4 ε=2.512×10-4 Volt

Q. A wheel with $20$ metallic spokes each $1 m$ long is rotated with a speed of $120 r p m$ in a plane perpendicular to a magnetic field of $0.4 G$ . The induced emf between the axle and rim of the wheel will be, $(1 G = 1 0^{- 4} T)$

$2.51 \times 1 0^{- 4} V$

$2.51 \times 1 0^{- 5} V$

$4.0 \times 1 0^{- 5} V$

$2.51 V$

$ε = \frac{1}{2} B ω r^{2}$
$ε = \frac{1}{2} \times (0.4 \times 1 0^{- 4}) \times (2 π [\frac{120}{60}]) (1)^{2}$
$ε = 0.8 π \times 1 0^{- 4}$
$ε = 2.512 \times 1 0^{- 4}$ Volt

Q. A wheel with 20 metallic spokes each 1m long is rotated with a speed of 120rpm in a plane perpendicular to a magnetic field of 0.4G. The induced emf between the axle and rim of the wheel will be, (1G=10−4T)

2.51×10−4V

2.51×10−5V

4.0×10−5V

2.51V