Introduction:
When a body is immersed in a fluid, it experiences an upward force known as the upthrust or buoyant force. The magnitude of this force depends on the density of the fluid. In this case, we need to determine the liquid in which the body will experience maximum upthrust and which liquid will make the body weigh more.

(a) Maximum Upthrust:
The upthrust experienced by a body is given by the formula:
Upthrust = Volume of fluid displaced × Density of fluid × Acceleration due to gravity

Since the volume of the body remains constant, the upthrust depends on the density of the fluid. The maximum upthrust will be experienced when the body is immersed in a fluid with the highest density.

Comparing the density of water, kerosene, and copper sulphate solution, we find that the density of copper sulphate solution is the highest. Therefore, the body will have maximum upthrust when it is immersed in copper sulphate solution.

(b) Weight of the Body:
The weight of a body is the force with which it is pulled towards the center of the Earth. It is given by the formula:
Weight = Mass × Acceleration due to gravity

The weight of a body depends on its mass and the acceleration due to gravity, which remain constant. Therefore, the weight of the body will be the same regardless of the liquid it is immersed in.

However, when the body is immersed in a fluid, it experiences an upward force (upthrust) in addition to its weight. The apparent weight of the body is the difference between its weight and the upthrust.

When the body is immersed in a liquid, it displaces some of the liquid, and the upthrust is equal to the weight of the displaced fluid. Since the density of copper sulphate solution is the highest, the body will displace a smaller volume of copper sulphate solution compared to water or kerosene. Therefore, the upthrust experienced by the body will be the least when it is immersed in copper sulphate solution.

Hence, the body will weigh more when immersed in copper sulphate solution compared to water or kerosene.

Conclusion:
(a) The body will have maximum upthrust when immersed in copper sulphate solution.
(b) The body will weigh more when immersed in copper sulphate solution compared to water or kerosene.

A-1 b-3