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,
1. the velocity of a fluid particle remains constant.

2. the velocity of all fluid particles crossing a given position is constant.

3. the velocity of all fluid particles at a given instant is constant.

4. the speed of a fluid particle remains constant. 

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°, Ethyl alcohol glass is 0°, Mercury glass is 140° and Methyliodide-glass is 30°. 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,
(a) the net force on it is zero.

(b) there is a net downward force.

(c) the potential energy is less than that of a molecule inside.

(d) the potential energy is more than that of a molecule inside.

Choose the correct alterative/s:

1. (b, c)

2. (b, d)

3. (c, d)

4. (a, d)

Pressure is a scalar quantity, because

(a) it is the ratio of force to the area and both force and area are vectors.

(b) it is the ratio of the magnitude of the force to the area.

(c) it is the ratio of the component of the force normal to the area.

(d) it does not depend on the size of the area chosen.

Choose the correct alterative/s:

1. (b, c)

2. (a, d)

3. (b, d)

4. (c, d)

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

The distances l and h are shown in the figure. After some time, the coin falls
into the water. Then,

(a) l decreases

(b) h decreases

(c) l increases

(d) h increases

Choose the correct alterative/s:

1. (b, c)

2. (a, d)

3. (c, d)

4. (a, b)

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?
1. (b, c)
2. (a, d)
3. (c, d)
4. (a, b)

Streamline flow is more likely for liquids with
(a) high density.

(b) high viscosity.

(c) low density.

(d) low viscosity.

Choose the correct alterative/s:

1. (a, b)

2. (c, d)

3. (b, c)

4. (a, d)