Law of Floatation

Q.

A beaker is filled with water to its brim. A child while playing drops his ball of mass 1 kg into it and eventually ends up with wetting himself with water. He weighs the water fallen on him and found it to be 1 N. Find the buoyant force experienced by the ball. (Assume that the ball drops slowly)

1. 1 N

2. 2 N

3. 3 N

4. 4 N

Q.

Archimedes' principle states that: "The upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the volume of the fluid that the body displaces."

1. True

2. False

Q.

In what condition does an object float in a liquid?

1. When density of the object is less than that of the liquid.
2. When density of the object is greater than that of liquid.
3. When the object displaces a volume of liquid more than its own volume.
4. When gravitational force is greater than buoyant force.

Q. The figures below show that a submarine can either sink or float. What is the relationship between the weight of submarine and the upthrust when the submarine sinks in water?

1. Weight of submarine = Upthrust.
2. Weight of submarine > Upthrust.
3. Weight of submarine < Upthrust.
4. Weight of submarine $\le$ Upthrust.

Q.

Pick out the option which is not an application of Archimedes principle.

1. It is used in designing of ship and submarines

2. In lactometers, to determine the purity of milk

3. In hydrometers to determine density of fluids

4. All of the above

Q. Consider two point masses separated by a particular distance. Now, if the masses are tripled, and the distance of separation is also tripled, then what will happen to the gravitational force between them?

1. It gets tripled.
2. It increases by 9 times.
3. It decreases by 9 times.
4. It remains the same.

Q. In a bucket full of water, a block weighing $50N$ was immersed. Water weighing $5N$ is spilled out of the bucket. Calculate the buoyant force.

1. $4N$
2. $5N$
3. $6N$
4. $8N$

Q.

When does a body float in a fluid?

1. When the weight of the body is greater than the buoyant force.

2. When the weight of the body is less than the buoyant force.

3. When the density of the body is more the fluid in which it is immersed.

4. When the density of the body is less than the fluid in which it is immersed.

Q.

A body while floating sinks deeper in a liquid of high density than in a liquid of low density.

1. True

2. False

Q.

The apparent weight of the floating body is zero.

1. True

2. False