Q$4)$ Select a suitable $02$ series radial contact deep groove ball bearing for a shaft intended for continuous one shift $(8$ hrs per day$)$ operation for $15$ years, assuming $250$ working days in a year and standard $90\%$ reliability. The shaft operates at $1800$ rpm with radial load $1\mathrm{.}5$ kN and thrust load $1\mathrm{.}2$ kN with light to moderate impact.

$[18]$