Answer: (a) 2N
Archimedes’ principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether partially or fully submerged, is equal to the weight of the fluid that the body displaces and acts in the upward direction at the center of mass of the displaced fluid.
According to archimedes principle,
Object of weight displace d by liquid = weight in air – weight in liquid
= 10N – 8N