When the water is swirling, why does it take the shape of a funnel with a depression in the centre?

L. Srihari, Bengaluru

Why does our voice become shaky as we become old?

N. Nikhita, Chennai

In motor bikes why do we use two separate disc brake controls for front and back instead of one pedal as in a car for all the four wheels?

Abhinav Narasimhan, Ambur, Tamil Nadu

Clouds contain tiny water drops which are heavier than air. Then how do they remain suspended and do not fall at once?

S.P.S. Jain, Greater Noida, Uttar Pradesh

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