Streamline Flow

Q. An ideal gas is expanding such that $P{T}^2=\text{constant}$. The coefficient of volumetric expansion of the gas is

1. $\frac{1}{T}$
2. $\frac{2}{T}$
3. $\frac{3}{T}$
4. $\frac{4}{T}$

Q.

What are the different types of flow?

Q.

What is viscous force?

Q. Streamline flow is more likely for liquids with

1. high density and high viscosity
2. low density and low viscosity
3. high density and low viscosity
4. low density and high viscosity

Q.

Why is it dangerous to stand on the edge of platform near the line, when the train is passing by?

Q. Water from a pipe is coming at a rate of $100litres$ per minute. If the radius of the pipe is $5cm$, the Reynolds number for the flow is of the order of (density of water $=1000kg/m^3$, coefficient of viscosity of water $=1mPa$).

1. ${10}^6$
2. ${10}^3$
3. ${10}^4$
4. ${10}^2$

Q.

Water flows at a speed of $6cm{s}^{-1}$ through a tube of radius 1 cm. Coefficient of viscosity of water at room temperature is 0.01 poise. Calculate the Reynolds number. Is it a steady flow?

Q.

The study of fluids in motion is called ____.

Q.

In the state of weightlessness, a capillary tube is dipped in water, then water

1. Will rise to same height as at atmospheric pressure

2. Will not rise at all

3. Will rise to less height than at atmospheric pressure

4. Will rise up to the upper end of the capillary tube of any length

Q. A transparent solid sphere of radius $2\text{cm}$ and density $\rho$ floats in a transparent liquid of density $2\rho$ kept in a beaker. The bottom of the beaker is spherical in shape with radius of curvature $8\text{cm}$ and is silvered to make it a concave mirror as shown in the figure. When an object is placed at a distance of $10\text{cm}$ directly above the centre of the sphere $C$, its final image coincides with it. Find approximate value of $h$, the height of the liquid surface in the beaker from the apex of the bottom. Consider the paraxial rays only. The refractive index of the sphere is $\frac{3}{2}$ and that of the liquid is $\frac{4}{3}$.

1. $17\text{cm}$
2. $11\text{cm}$
3. $13\text{cm}$
4. $15\text{cm}$

Q.

Given below are some regular shaped objects of uniform density. Mark the position of centre of gravity in each of these objects.

Q. Which of the following is not the property of an ideal fluid?

1. Fluid flow is irrotational
2. Fluid flow is streamline
3. Fluid is viscous
4. Fluid is incompressible

Q. For a laminar flow of fluid, identify the correct statement regarding the magnitude and direction of the velocity at a given point in the fluid.

1. Both are not constant
2. Only magnitude is constant
3. Only direction of velocity is constant
4. Both magnitude and direction of velocity are constant

Q.

Which of the following cannot be explained on the basis of Bernoullis principle?

1. Lift on an aircrafts wing

2. Ink filler

3. Swing of a cricket ball

4. Atomizer

Q.

Bucket to a bucket of water is suspended from a spring balance. what happens to reading of balance a)when piece of stone is suspended from string is immersed in water without touching bucket.b)when piece of lead or cork is put in water in the bucket

Q. Streamline flow is more likely for liquids with

1. high density and high viscosity
2. low density and low viscosity
3. high density and low viscosity
4. low density and high viscosity

Q. The velocity beyond which the flow of the liquid becomes turbulent is called velocity.

1. critical
2. terminal
3. instantaneous

Q. A pump motor is used to deliver water at a certain rate from a given pipe. To obtain twice as much water from the same pipe in same time, Power of the motor has to be increased to?

Q. The velocity of water in a river from its banks to its center.

1. decreases
2. increases
3. remains unchanged

Q.

The weight of an aeroplane flying in the air is balanced by

1. Vertical component of the thrust created by air currents striking the lower surface of the wings

2. Force due to reaction of gases ejected by the revolving propeller

3. Upthrust of the air which will be equal to the weight of the air having the same volume as the plane

4. Force due to the pressure difference between the upper and lower surfaces of the wings created by different air speeds on the surfaces

Q. A container contains two immiscible liquids of density ${\rho }_1$ and ${\rho }_2$ $({\rho }_2>{\rho }_1)$. A capillary of radius $r$ is inserted in the liquids so that its bottom reaches upto denser liquid. Denser liquid rises in capillary and attains a height $h$ which is also equal to column length of lighter liquid. Assuming zero contact angle, find surface tension of heavier liquid.

1. $\frac{r{\rho }_{2}gh}{2}$
2. $\frac{r}{2}({\rho }_2-{\rho }_1)gh$
3. $2\pi r{\rho }_{2}gh$
4. $2\pi r({\rho }_2-{\rho }_1)gh$

Q.

Give few examples of man-made streamlined bodies.

Q.

Steady flow is also called?

1. Turbulent flow

2. Streamline flow

3. Rotational flow

4. Viscous flow

Q. I have a hollow sphere filled with water. I roll it on a smooth surface and a rough surface. Will the water inside the sphere rotate in any of the cases? Will the rotation of the water inside the sphere depend on the velocity with which the it is rolled?

Q. A vertical U-tube is rotated about the vertical axis passing through the left limb, with an angular speed $\omega$ such that the liquid columns in the limbs have height $hand3h$ where h is 205 mm, as shown in figure. The value of $\omega$ (in rad/s) is (Take $g=10m{s}^{-2}$)

1. 5.55
2. 2.44
3. 1.55
4. 3.55

Q. A fully loaded Boeing aircraft has a mass of $3.3\times {10}^5$ kg, its total wing area is $500m^2$. It is in level flight with speed of 960 km/h. (a) Estimate the pressure difference between the lower and upper surfaces of the wings. (b) Estimate the fractional increase in the speed of the air on the upper surface of the wing relative to lower surface. (The density of air is $\rho =1.2kg{m}^{-3}$)

Q. A tank with a small orifice contains oil on top of water. It is immersed in a large tank of the same oil. Water flows through the hole. Assuming the level of oil outside the tank above orifice does not change. a. What is the velocity of this flow initially? b. When the flow stops, what would be the position of the oil-water interface in the tank? c. Determine the time at which the flow stops? Density of oil $=800kg/m^3$.

Q. A cylindrical vessel of $90\text{cm}$ height is filled upto the brim. It has four holes 1, 2, 3, 4 which are respectively at heights of $20\text{cm},30\text{cm},40\text{cm}$ and $50\text{cm}$ from the horizontal floor $PQ$. The water falling at the maximum horizontal distance from the vessel comes from

1. Hole number 4
2. Hole number 3
3. Hole number 2
4. Hole number 1

Q. When water flows through a pipe, which layer moves fastest?

Q. The flow rate of a water from a tap of diameter $1.25cm$ is $0.48L/min$. If the coefficient of viscosity of water is ${10}^{-3}Pas$, what is the nature of flow of water?