Buoyant Force

Q. Which one of the following statements is true ?

1. Both light and sound waves in air are longitudinal.
2. Both light and sound waves in air are transverse.
3. Both light and sound waves can travel in vacuum.
4. The sound waves in air are longitudinal while the light waves are transverse.

Q. A simple pendulum has a time period $T$ in vacuum. Its time period when it is completely immersed in a liquid of density one-eighth of the density of the material of the bob is

1. $\sqrt{\frac{7}{8}}T$
2. $\sqrt{\frac{5}{8}}T$
3. $\sqrt{\frac{3}{8}}T$
4. $\sqrt{\frac{8}{7}}T$

Q. A uniform cubical block of density ${\rho }_b\left(\text{in g/cc}\right)$ and length a is released from rest from the position where one of its horizontal surface (lower) just touches the water (density ${\rho }_w=1\text{g/cc}$). The time period of oscillation of the block is $({\rho }_b=\frac{2}{3}\text{g/cc},\text{neglect viscosity and surface tension})$

1. $2\pi \sqrt{\frac{p_{b}a}{p_{w}g}}$
2. $2\pi \sqrt{\frac{p_{w}a}{p_{b}g}}$
3. $\frac{4\pi }{3}\sqrt{\frac{p_{b}a}{p_{w}g}}+\frac{p_b}{p_w-p_b}\sqrt{\frac{4p_{w}a}{3p_{b}g}}$
4. $\frac{2\pi }{3}\sqrt{\frac{p_{b}a}{p_{w}g}}+\frac{p_b}{p_w-p_b}\sqrt{\frac{2p_{w}a}{3p_{b}g}}$

Q.

Which of the following statements are true.

1. Larger the volume of a body submerged in a fluid, greater the upthrust.

2. when the upthrust is greater than the weight of a body, the body sinks.

3. The upthrust depends on the density of the fluid.

4. The upthrust on a body acts in the upward direction.

Q.

A body weighs 5 kg in air and 3 kg in water, calculate the upthrust experienced by the body.

1. 5N

2. 2N

3. 3N

4. 4N

Q. Which of the following factors affect the upthrust acting on a body submerged in a fluid?

1. The density of the liquid
2. The volume of the body submerged
3. The mass of the fluid
4. The colour of the object submerged

Q.

Upthrust is equal to the weight of the displaced liquid.

1. True

2. False

Q. Two objects of different materials are completely immersed in​ water. If both objects experience the same buoyant force, then​ they must have the same _______.

1. volume
2. colour
3. weight
4. mass

Q.

Upward force acting on a body submerged in a liquid is called ___.

Q.

What happens to the weight of a body when it is immersed in a liquid.

1. Remains the same.

2. Decreases.

3. Increases

4. Depends on the fluid or the body submerged.