A tall cylinder is filled with viscous oil. A round pebble is dropped from the top with zero initial velocity. From the plot shown in the figure, indicate the one that represents the velocity \((v)\) of the pebble as a function of time \((t).\)
 

1.		2.
3.		4.

Which of the following diagrams does not represent a streamline flow?
 

1.		2.
3.		4.

Along a streamline,

An ideal fluid flows through a pipe of circular cross-section made of two sections with diameters \(2.5\) cm and \(3.75\) cm. The ratio of the velocities in the two pipes is:
1. \(9:4\)
2. \(3:2\)
3. \(\sqrt{3}:\sqrt{2}\)
4. \(\sqrt{2}:\sqrt{3}\)

The angle of contact at the interface of the water glass is \(0^{\circ},\) ethyl-alcohol glass is \(0^{\circ},\) mercury-glass is \(140^{\circ}\) and methyl iodide-glass is \(30^{\circ}.\) A glass capillary is put in a trough containing one of these four liquids is observed that the meniscus is convex. The liquid in the trough is:
1. water
2. ethyl alcohol
3. mercury
4. methyl iodide

For a surface molecule,

Choose the correct alterative/s:
1. (b), (c)
2. (b), (d)
3. (c), (d)
4. (a), (d)

A wooden block with a coin placed on its top, floats in water as shown in the figure.

The distances \(\mathrm{l}\) and \(\mathrm{h}\) are shown in the figure. After some time, the coin falls
into the water. Then,

Choose the correct alterative/s:

With an increase in temperature, the viscosity of:
(a) gases decreases.
(b) liquids increases.
(c) gases increases.
(d) liquids decreases.
Which of the following options is/are correct?

Streamline flow is more likely for liquids with,

Choose the correct option:
1. (a), (b)
2. (c), (d)
3. (b), (c)
4. (a), (d)

A liquid does not wet the solid surface if the angle of contact is:
1. equal to $\mathrm{}$\(45^{\circ}\)
2. equal to \(60^{\circ}\)$\mathrm{}$
3. greater then \(90^{\circ}\)$\mathrm{}$
4. zero