The correct option is B 0.636 m
A bicycle wheel makes 500 revolutions in moving 1 km
i.e., 500 revolutions = 1000 m
1 revolution =1000500=2 m
∴ Circumference of wheel = 2 m
According to question
2πr=2
⇒2×227×r=2
⇒447×r=2
⇒r=2×744=722
∴ Diameter of the wheel = 2r
=2×722=711=0.636 m