Why are spokes fitted in a cycle wheel?

Why are carbon and nitrogen cycles gaseous cycles?

Would a defoliated plant respond to photoperiodic cycle? Why?

Why a point on a rotating wheel cannot be considered as executing SHM?

A large steel wheel is to be fitted on a shaft of the same material . At 27^@C , the outer diameter of the shaft is 8.70 cm and the diameter of the central hole in the wheel is 8.69 cm. The shaft is cooled using 'dry ice'. At what temperature of the shaft does the wheel slip on the shaft? Assume coefficient of linear expansion of the steel is to be constant over the required temperature range : alpha_(steel) = 1.20 xx 10^-5 K .

Although direction of current through the armature reverses after each half cycle, yet it keeps on rotating in one direction. Why?

Some of these terms/ chemicals are associated with the C_4 cycle, explain. Calvin cycle

Calculated the angle between a pair of consecutive spokes on a wheel with 15 spokes.

Why are nutrient cycles in nature called biotechnological cycles?