Q. No.A metal block of area \(0.10~\text{m}^{2}\) is connected to a \(0.010~\text{kg}\) mass via a string that passes over an ideal pulley (considered massless and frictionless), as in the figure below. A liquid film with a thickness of \(0.30~\text{mm}\) is placed between the block and the table. When released the block moves to the right with a constant speed of \(0.085~\text{m/s}.\) The coefficient of viscosity of the liquid is:
1. \(4.45 \times 10^{-2}~\text{Pa-s}\)
2. \(4.45 \times 10^{-3}~\text{Pa-s}\)
3. \(3.45 \times 10^{-2}~\text{Pa-s}\)
4. \(3.45 \times 10^{-3}~\text{Pa-s}\)
1. \(4.45 \times 10^{-2}~\text{Pa-s}\)
2. \(4.45 \times 10^{-3}~\text{Pa-s}\)
3. \(3.45 \times 10^{-2}~\text{Pa-s}\)
4. \(3.45 \times 10^{-3}~\text{Pa-s}\)
The velocity of a small ball of mass \(M\) and density \(d\), when dropped in a container filled with glycerine becomes constant after some time. If the density of glycerine is \(d\over 2\) then the viscous force acting on the ball will be:
| 1. | \(\frac{3Mg}{2}\) | 2. | \(2Mg\) |
| 3. | \(\frac{Mg}{2}\) | 4. | \(Mg\) |
A liquid can easily change its shape but a solid can not because:
| 1. | the density of a liquid is smaller than that of a solid. |
| 2. | the forces between the molecules is stronger in solid than in liquids. |
| 3. | the atoms combine to form bigger molecules in a solid. |
| 4. | the average separation between the molecules is larger in solids. |
A liquid does not wet the solid surface if the angle of contact is:
1. equal to \(45^{\circ}\)
2. equal to \(60^{\circ}\)
3. greater then \(90^{\circ}\)
4. zero
Given below are two statements:
| Assertion (A): | Water flows through a smooth horizontal tube with a narrowing cross-section and its pressure increases. |
| Reason (R): | Bernoulli's equation for fluids states that \(P+\dfrac{1}{2}\rho v^2+\rho gh= \) constant along a streamline. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
| 1. | Soap bubbles have two air-liquid interfaces. |
| 2. | Liquid drops have one air-liquid interface. |
| 3. | Air cavity inside a liquid has one air-liquid interface. |
| 4. | Air cavity inside a liquid has two air-liquid interfaces. |
(consider no loss anywhere)
1. \(64\pi R^{2}T\)
2. \(9\pi R^{2}T\)
3. \(32\pi R^{2}T\)
4. \(72\pi R^{2}T\)
1. \(3h\)
2. \(2h\)
3. \(h\)
4. \(\dfrac {3h} 2\)
1. \(2.5~\text{cm}\)
2. \(2.8~\text{cm}\)
3. \(3.0~\text{cm}\)
4. \(3.2~\text{cm}\)
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) |
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