An object of weight 500 N is floating in a liquid. The magnitude of buoyant force acting on it is

1. The buoyant force is the upward force exerted on an object wholly or partly immersed in a fluid. This upward force is also called Upthrust.
2. An object floats in a liquid if it receives equal and an opposite upward force called buoyant force from the liquid.
3. In other words, an object floats in a liquid when its weight is counteracted by the buoyant force.
4. From the given, the weight of the object is 500 N.
5. Hence, the buoyant force acting on the object is also equal to 500 N.