Grade 11 : Physics - Fluids (Set 2)

Back to Quizzes

Complete Syllabus Question Paper

Grade 11 : Physics - Fluids (Set 2)— Questions & Detailed Solutions

A swimmer dives to a depth of 5 m below the surface of a freshwater lake.
Calculate the gauge pressure experienced by the swimmer at this depth. (Take $\rho = 1000\text{ kg/m}^3$ and $g = 10m/s^2$)

(A)

20 kPa

(B)

50 kPa

(C)

100 kPa

(D)

5 kPa

View Correct Answer & Detailed Solution

✓ Correct Option: (B)

Explanation:Gauge pressure is given by $P = \rho g h$. Substituting the given values: $$P = 1000 \times 10 \times 5 = 50,000\text{ Pa} = 50\text{ kPa}$$ Thus, option B is correct.

What is the standard SI unit of surface tension?

(A)

$\text{N}\cdotm$

(B)

$\text{N/m}$

(C)

$\text{N/m}^2$

(D)

$\text{J/m}$

View Correct Answer & Detailed Solution

✓ Correct Option: (B)

Explanation:Surface tension is defined as force per unit length ($T = F/L$). Therefore, its SI unit is Newtons per meter ($\text{N/m}$).

Which fundamental principle directly explains the operating mechanism of a hydraulic lift?

(A)

Bernoulli's Principle

(B)

Archimedes' Principle

(C)

Pascal's Law

(D)

Torricelli's Law

View Correct Answer & Detailed Solution

✓ Correct Option: (C)

Explanation:Pascal's Law states that pressure applied to an enclosed fluid is transmitted undiminished throughout the fluid, which is the foundational principle of hydraulic machines.

A solid metallic sphere of volume $0.02m^3$ is completely submerged in water.
What is the magnitude of the buoyant force acting on the sphere? (Take $\rho_{\text{water}} = 1000\text{ kg/m}^3$ and $g = 10m/s^2$)

(A)

200 N

(B)

100 N

(C)

500 N

(D)

20 N

View Correct Answer & Detailed Solution

✓ Correct Option: (A)

Explanation:By Archimedes' principle, buoyant force $F_b = \rho_{\text{fluid}} V_{\text{submerged}} g$. $$F_b = 1000 \times 0.02 \times 10 = 200\text{ N}$$

Water flows in an incompressible, streamline manner through a horizontal pipe whose cross-sectional area decreases from $0.04m^2$ to $0.01m^2$.
If the speed of water in the wider region is 3 m/s, what is its speed in the narrower region?

(A)

6 m/s

(B)

8 m/s

(C)

12 m/s

(D)

15 m/s

View Correct Answer & Detailed Solution

✓ Correct Option: (C)

Explanation:Using the equation of continuity $A_1 v_1 = A_2 v_2$: $$0.04 \times 3 = 0.01 \times v_2 \implies v_2 = \frac{0.12}{0.01} = 12\text{ m/s}$$

A open water tank has a small orifice on its vertical wall at a depth of 5 m below the free surface of water.
What is the speed of efflux of water emerging from the orifice? (Take $g = 10m/s^2$)

(A)

5 m/s

(B)

10 m/s

(C)

14.1 m/s

(D)

20 m/s

View Correct Answer & Detailed Solution

✓ Correct Option: (B)

Explanation:By Torricelli's Law, the speed of efflux is $v = \sqrt{2gh}$. $$v = \sqrt{2 \times 10 \times 5} = \sqrt{100} = 10\text{ m/s}$$

What is the correct expression for the excess pressure inside a spherical soap bubble of radius $r$ having surface tension $T$?

(A)

$\frac{T}{r}$

(B)

$\frac{2T}{r}$

(C)

$\frac{4T}{r}$

(D)

$\frac{8T}{r}$

View Correct Answer & Detailed Solution

✓ Correct Option: (C)

Explanation:A soap bubble has two free liquid-air interfaces (inner and outer). Thus, excess pressure is $\Delta P = 2 \times \left(\frac{2T}{r}\right) = \frac{4T}{r}$.

According to Stokes' Law, the retarding viscous force $F$ acting on a small spherical ball of radius $r$ moving with terminal velocity $v$ in a fluid of viscosity $\eta$ is:

(A)

$3\pi\eta r v$

(B)

$6\pi\eta r v$

(C)

$6\pi\eta r^2 v$

(D)

$4\pi\eta r v^2$

View Correct Answer & Detailed Solution

✓ Correct Option: (B)

Explanation:Stokes' Law gives the viscous force on a spherical body moving through a viscous medium as $F = 6\pi\eta r v$.

A wooden block of density $800\text{ kg/m}^3$ floats calmly in water of density $1000\text{ kg/m}^3$.
What percentage of the block's total volume remains submerged under water?

(A)

20%

(B)

50%

(C)

80%

(D)

100%

View Correct Answer & Detailed Solution

✓ Correct Option: (C)

Explanation:For floating bodies, $\frac{V_{\text{submerged}}}{V_{\text{total}}} = \frac{\rho_{\text{body}}}{\rho_{\text{fluid}}} = \frac{800}{1000} = 0.8 = 80%$.

Q10

What are the dimensional formulas for the coefficient of dynamic viscosity ($\eta$)?

(A)

$[\text{M L T}^{-1}]$

(B)

$[\text{M L}^{-1} \text{T}^{-1}]$

(C)

$[\text{M L}^{-1} \text{T}^{-2}]$

(D)

$[\text{M L}^2 \text{T}^{-1}]$

View Correct Answer & Detailed Solution

✓ Correct Option: (B)

Explanation:From Newton's law of viscosity $F = \eta A \frac{dv}{dx}$, we have $[\eta] = \frac{[F]}{[A][dv/dx]} = \frac{\text{M L T}^{-2}}{\text{L}^2 \cdot \text{T}^{-1}} = [\text{M L}^{-1} \text{T}^{-1}]$.

Q11

In a hydraulic press, the smaller piston has a cross-sectional area of $0.05m^2$ and the larger piston has an area of $1.0m^2$.
If a force of 100 N is applied to the smaller piston, what upward force is exerted by the larger piston?

(A)

500 N

(B)

1000 N

(C)

2000 N

(D)

4000 N

View Correct Answer & Detailed Solution

✓ Correct Option: (C)

Explanation:Using Pascal's principle, $\frac{F_1}{A_1} = \frac{F_2}{A_2} \implies \frac{100}{0.05} = \frac{F_2}{1.0} \implies F_2 = 2000\text{ N}$.

Q12

A thin soap film has a surface tension $T = 0.05\text{ N/m}$.
Calculate the work done in expanding the area of the soap film by $0.02m^2$.

(A)

$1 \times 10^{-3}\text{ J}$

(B)

$2 \times 10^{-3}\text{ J}$

(C)

$4 \times 10^{-3}\text{ J}$

(D)

$5 \times 10^{-3}\text{ J}$

View Correct Answer & Detailed Solution

✓ Correct Option: (B)

Explanation:A soap film has 2 surfaces, so total increase in surface area $\Delta A_{\text{total}} = 2 \times 0.02 = 0.04m^2$. Work done $W = T \times \Delta A_{\text{total}} = 0.05 \times 0.04 = 2 \times 10^{-3}\text{ J}$.

Q13

For fluid flow through a pipe, turbulent flow generally occurs when the Reynolds number ($R_e$) is greater than approximately:

(A)

100

(B)

500

(C)

1000

(D)

3000

View Correct Answer & Detailed Solution

✓ Correct Option: (D)

Explanation:In pipe flow, flow is streamline (laminar) for $R_e < 2000$ and becomes turbulent when $R_e > 3000$.

Q14

If the radius of a capillary tube is reduced to half its original value, how does the height of capillary rise change for the same liquid?

(A)

It is halved

(B)

It remains unchanged

(C)

It is doubled

(D)

It is quadrupled

View Correct Answer & Detailed Solution

✓ Correct Option: (C)

Explanation:Capillary rise is given by $h = \frac{2T \cos \theta}{r \rho g}$. Since $h \propto \frac{1}{r}$, halving $r$ doubles the height $h$.

Q15

At a certain point underwater, the gauge pressure measured is 49 kPa. The prevailing atmospheric pressure is 101 kPa.
What is the absolute pressure at that depth?

(A)

52 kPa

(B)

101 kPa

(C)

150 kPa

(D)

200 kPa

View Correct Answer & Detailed Solution

✓ Correct Option: (C)

Explanation:Absolute pressure is the sum of atmospheric pressure and gauge pressure: $$P_{\text{abs}} = P_{\text{atm}} + P_{\text{gauge}} = 101\text{ kPa} + 49\text{ kPa} = 150\text{ kPa}$$

Q16

Bernoulli's equation for steady, non-viscous, incompressible fluid flow is a direct formulation of which fundamental conservation law?

(A)

Conservation of Mass

(B)

Conservation of Linear Momentum

(C)

Conservation of Energy

(D)

Conservation of Angular Momentum

View Correct Answer & Detailed Solution

✓ Correct Option: (C)

Explanation:Bernoulli's equation states that the total mechanical energy per unit volume of an ideal moving fluid remains constant along a streamline, reflecting conservation of energy.

Q17

How does the terminal velocity $v_t$ of a small spherical ball falling through a viscous medium depend on its radius $r$?

(A)

$v_t \propto r$

(B)

$v_t \propto r^2$

(C)

$v_t \propto \sqrt{r}$

(D)

$v_t \propto \frac{1}{r}$

View Correct Answer & Detailed Solution

✓ Correct Option: (B)

Explanation:Equating net effective downward force to viscous force gives $v_t = \frac{2}{9}\frac{r^2 (\rho - \sigma)g}{\eta}$. Thus, terminal velocity is directly proportional to $r^2$.

Q18

What is the excess pressure inside a single liquid drop of radius $R$ and surface tension $T$?

(A)

$\frac{T}{R}$

(B)

$\frac{2T}{R}$

(C)

$\frac{4T}{R}$

(D)

$\frac{T}{2R}$

View Correct Answer & Detailed Solution

✓ Correct Option: (B)

Explanation:A liquid drop has only one free liquid-air surface, so the excess pressure inside it is $\Delta P = \frac{2T}{R}$.

Q19

What is the angle of contact for pure water in contact with clean glass?

(A)

$0^\circ$

(B)

$45^\circ$

(C)

$90^\circ$

(D)

$135^\circ$

View Correct Answer & Detailed Solution

✓ Correct Option: (A)

Explanation:Pure water completely wets clean glass surfaces, resulting in a concave meniscus and an angle of contact of approximately $0^\circ$.

Q20

A Venturi meter is a practical device designed to measure which physical quantity?

(A)

Density of a liquid

(B)

Static pressure only

(C)

Rate of flow of liquid through a pipe

(D)

Viscosity of a liquid

View Correct Answer & Detailed Solution

✓ Correct Option: (C)

Explanation:A Venturi meter operates based on Bernoulli's principle to measure the speed or volume flow rate of a liquid passing through a pipe.

Grade 11 : Physics - Fluids (Set 2)

Grade 11 : Physics - Fluids (Set 2)— Questions & Detailed Solutions

A swimmer dives to a depth of 5 m below the surface of a freshwater lake.
Calculate the gauge pressure experienced by the swimmer at this depth. (Take $\rho = 1000\text{ kg/m}^3$ and $g = 10m/s^2$)

What is the standard SI unit of surface tension?

Which fundamental principle directly explains the operating mechanism of a hydraulic lift?

A solid metallic sphere of volume $0.02m^3$ is completely submerged in water.
What is the magnitude of the buoyant force acting on the sphere? (Take $\rho_{\text{water}} = 1000\text{ kg/m}^3$ and $g = 10m/s^2$)

Water flows in an incompressible, streamline manner through a horizontal pipe whose cross-sectional area decreases from $0.04m^2$ to $0.01m^2$.
If the speed of water in the wider region is 3 m/s, what is its speed in the narrower region?

A open water tank has a small orifice on its vertical wall at a depth of 5 m below the free surface of water.
What is the speed of efflux of water emerging from the orifice? (Take $g = 10m/s^2$)

What is the correct expression for the excess pressure inside a spherical soap bubble of radius $r$ having surface tension $T$?

According to Stokes' Law, the retarding viscous force $F$ acting on a small spherical ball of radius $r$ moving with terminal velocity $v$ in a fluid of viscosity $\eta$ is:

A wooden block of density $800\text{ kg/m}^3$ floats calmly in water of density $1000\text{ kg/m}^3$.
What percentage of the block's total volume remains submerged under water?

What are the dimensional formulas for the coefficient of dynamic viscosity ($\eta$)?

In a hydraulic press, the smaller piston has a cross-sectional area of $0.05m^2$ and the larger piston has an area of $1.0m^2$.
If a force of 100 N is applied to the smaller piston, what upward force is exerted by the larger piston?

A thin soap film has a surface tension $T = 0.05\text{ N/m}$.
Calculate the work done in expanding the area of the soap film by $0.02m^2$.

For fluid flow through a pipe, turbulent flow generally occurs when the Reynolds number ($R_e$) is greater than approximately:

If the radius of a capillary tube is reduced to half its original value, how does the height of capillary rise change for the same liquid?

At a certain point underwater, the gauge pressure measured is 49 kPa. The prevailing atmospheric pressure is 101 kPa.
What is the absolute pressure at that depth?

Bernoulli's equation for steady, non-viscous, incompressible fluid flow is a direct formulation of which fundamental conservation law?

How does the terminal velocity $v_t$ of a small spherical ball falling through a viscous medium depend on its radius $r$?

What is the excess pressure inside a single liquid drop of radius $R$ and surface tension $T$?

What is the angle of contact for pure water in contact with clean glass?

A Venturi meter is a practical device designed to measure which physical quantity?

Discussion 0

Enjoyed this content?

Grade 11 : Physics - Fluids (Set 2)

Grade 11 : Physics - Fluids (Set 2)— Questions & Detailed Solutions

A swimmer dives to a depth of 5 m below the surface of a freshwater lake.Calculate the gauge pressure experienced by the swimmer at this depth. (Take $\rho = 1000\text{ kg/m}^3$ and $g = 10m/s^2$)

What is the standard SI unit of surface tension?

Which fundamental principle directly explains the operating mechanism of a hydraulic lift?

A solid metallic sphere of volume $0.02m^3$ is completely submerged in water.What is the magnitude of the buoyant force acting on the sphere? (Take $\rho_{\text{water}} = 1000\text{ kg/m}^3$ and $g = 10m/s^2$)

Water flows in an incompressible, streamline manner through a horizontal pipe whose cross-sectional area decreases from $0.04m^2$ to $0.01m^2$.If the speed of water in the wider region is 3 m/s, what is its speed in the narrower region?

A open water tank has a small orifice on its vertical wall at a depth of 5 m below the free surface of water.What is the speed of efflux of water emerging from the orifice? (Take $g = 10m/s^2$)

What is the correct expression for the excess pressure inside a spherical soap bubble of radius $r$ having surface tension $T$?

According to Stokes' Law, the retarding viscous force $F$ acting on a small spherical ball of radius $r$ moving with terminal velocity $v$ in a fluid of viscosity $\eta$ is:

A wooden block of density $800\text{ kg/m}^3$ floats calmly in water of density $1000\text{ kg/m}^3$.What percentage of the block's total volume remains submerged under water?

What are the dimensional formulas for the coefficient of dynamic viscosity ($\eta$)?

In a hydraulic press, the smaller piston has a cross-sectional area of $0.05m^2$ and the larger piston has an area of $1.0m^2$.If a force of 100 N is applied to the smaller piston, what upward force is exerted by the larger piston?

A thin soap film has a surface tension $T = 0.05\text{ N/m}$.Calculate the work done in expanding the area of the soap film by $0.02m^2$.

For fluid flow through a pipe, turbulent flow generally occurs when the Reynolds number ($R_e$) is greater than approximately:

If the radius of a capillary tube is reduced to half its original value, how does the height of capillary rise change for the same liquid?

At a certain point underwater, the gauge pressure measured is 49 kPa. The prevailing atmospheric pressure is 101 kPa.What is the absolute pressure at that depth?

Bernoulli's equation for steady, non-viscous, incompressible fluid flow is a direct formulation of which fundamental conservation law?

How does the terminal velocity $v_t$ of a small spherical ball falling through a viscous medium depend on its radius $r$?

What is the excess pressure inside a single liquid drop of radius $R$ and surface tension $T$?

What is the angle of contact for pure water in contact with clean glass?

A Venturi meter is a practical device designed to measure which physical quantity?

Share This Quiz

Discussion 0

Enjoyed this content?

More Quizzes for Grade 11

Grade 11 : Mathematics - Sets (Set 2) | Concept of Maths

Grade 11 : Chemistry - Basic Concepts (Set 7) | Concept of Maths

Grade 11 : Biology - Morphology of Plants (Set 3)

Grade 11 : Biology - Morphology of Plants (Set 4)

Grade 11 : Mathematics - Sets (Set 2) | Concept of Maths

Grade 11 : Mathematics - Relations (Set 2) | Concept of Maths

A swimmer dives to a depth of 5 m below the surface of a freshwater lake.
Calculate the gauge pressure experienced by the swimmer at this depth. (Take $\rho = 1000\text{ kg/m}^3$ and $g = 10m/s^2$)

A solid metallic sphere of volume $0.02m^3$ is completely submerged in water.
What is the magnitude of the buoyant force acting on the sphere? (Take $\rho_{\text{water}} = 1000\text{ kg/m}^3$ and $g = 10m/s^2$)

Water flows in an incompressible, streamline manner through a horizontal pipe whose cross-sectional area decreases from $0.04m^2$ to $0.01m^2$.
If the speed of water in the wider region is 3 m/s, what is its speed in the narrower region?

A open water tank has a small orifice on its vertical wall at a depth of 5 m below the free surface of water.
What is the speed of efflux of water emerging from the orifice? (Take $g = 10m/s^2$)

A wooden block of density $800\text{ kg/m}^3$ floats calmly in water of density $1000\text{ kg/m}^3$.
What percentage of the block's total volume remains submerged under water?

In a hydraulic press, the smaller piston has a cross-sectional area of $0.05m^2$ and the larger piston has an area of $1.0m^2$.
If a force of 100 N is applied to the smaller piston, what upward force is exerted by the larger piston?

A thin soap film has a surface tension $T = 0.05\text{ N/m}$.
Calculate the work done in expanding the area of the soap film by $0.02m^2$.

At a certain point underwater, the gauge pressure measured is 49 kPa. The prevailing atmospheric pressure is 101 kPa.
What is the absolute pressure at that depth?