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 \(0^{\circ},\) 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,
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 the figure.
The distances \(\mathrm{l}\) and \(\mathrm{h}\) are shown in the figure. After some time, the coin falls
into the water. Then,
(a) | \(\mathrm{l}\) decreases |
(b) | \(\mathrm{h}\) decreases |
(c) | \(\mathrm{l}\) increases |
(d) | \(\mathrm{h}\) 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 option:
1. (a), (b)
2. (c), (d)
3. (b), (c)
4. (a), (d)