Consider the following statements:

I. The coefficient of viscosity is the only parameter through which the viscosity of the fluid is measured.

II. Negative sign of coefficient of viscosity indicates that the viscous force opposes the relative motion.

III. The SI unit of viscosity is $\mathrm{N}-{\mathrm{sm}}^{-2}$.

IV. $1$ poise $=0.1 \mathrm{N}-{\mathrm{sm}}^{-2}$.

Which of the statements given above are correct?

Materials for rain-proof coats and tents owe their water-proof properties to _____.

The following three questions consists of two statements, one labelled as Assertion (A) and the other as Reason (R). You are to examine these two statements carefully and select the answers using the codes given below:

Assertion (A): The ships of iron and the boats of wood float in water but the nails iron sink.

Reason (R): The special design and shape of the ship and the boat through which weight of displaced water are more than the weight of the ship and boat, due to which more force of buoyancy becomes operative and the ships or boats floats. But the weight of the water displaced by the nails is less than the weight of nails that is why nails sink.

The following three questions consists of two statements, one labelled as Assertion (A) and the other as Reason (R). You are to examine these two statements carefully and select the answers using the codes given below:

Assertion (A): If a piece of ice floats on a water surface, then its $\left(\frac{1}{10}\right)\mathrm{th}$ part of the total volume remains above the surface and $\left(\frac{9}{10}\right)\mathrm{th}$ part remains submerged.

Reason (R): This is because the ratio of the density of ice to the density of water is equal to the ratio of total volume of ice inside water to the total volume of ice.

The following three questions consists of two statements, one labelled as Assertion (A) and the other as Reason (R). You are to examine these two statements carefully and select the answers using the codes given below:

Assertion (A): When water flows in a uniform horizontal pipe, there is a fall in pressure of water along the pipe.

Reason (R): Force is required to maintain the motion of the liquid against frictional force.