What can be the effect of aquaplaning?

You answered correctly. Aquaplaning occurs when a layer of water builds up between your tires and the road, causing you to lose contact with the road surface. This leads to reduced steering control and makes braking much less effective. Importantly, aquaplaning reduces friction, so it does not increase tyre static friction as stated in answer 3. Always slow down in heavy rain and with worn tires to reduce the risk. If you experience aquaplaning, ease off the accelerator and avoid sudden steering or braking.