AIIMS 2012 Physics Question Paper for free online practice with solutions

Variation in g due to rotation of earth
g′=g−ω2Rcos2λ
At poles, λ=90° in the above expression, we get
gpole=g−ω2Rcos290°
∴gpole=g
i.e., there is no effect of rotational motion of the earth on the value of g at poles.