Mechanical Properties Of Fluid

According to Bernoulli's principle if air is blown between two suspended balls the air pressure between them decreases but pressure at the outside points remain same. So there is pressure difference across both the balls. So they move towards each other.

Rise of the oil in the wick of a lamp is due to surface tension

Here, 1 atm = 0.76 m of Hg = L m of water,

or,
or,

Rate of flow of liquid, .
Now, or

or

Terminal velocity ,

= Radius of ball of mass
= Terminal velocity of this ball
= Radius of ball of mass 64 m
= Terminal velocity of larger ball
Now, mass= density volume.
Volume ohhe larger ball is 64 times that of the smaller ball.
So,
or ,

or,

With the addition of impurities surface tension of a liquid may increase or decrease depending on the properties of impurities

Answer (c) both (i) and (ii) are correct

When raindrop moves downward through air, an upward drag (viscous) force acts on it. This force depends on velocity of the raindrop. After certain time, this force becomes equal to the weight of the raindrop and it falls with constant velocity.

According to Poiseuille's formula, rate of flow through a narrow tube
For given and
,
Here,
So,