Free Fluid Dynamics MCQs with Answers
363 Fluid Dynamics MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Fluid flow is described through speed, pressure and density, including steady flow and the equation of continuity for conserving mass. Bernoulli's equation relates pressure, speed and height, while fluid drag and terminal velocity explain why a falling object eventually moves at constant speed when drag balances its weight.
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Read the Fluid Dynamics notesFree MDCAT chapter notes with key terms363 questions Β· page 7 of 19
- A. kgm^-1 s
- B. kg m^-1s^-1
- C. kgms^-1
- D. kgΒ² m^-2s^-2
Explanation: The SI unit of the coefficient of viscosity, also known as dynamic viscosity, is expressed in kg m^-1s^-1.
Correct answer: kg m^-1s^-1- A. lower where the diameter is large
- B. higher where the diameter is large
- C. same throughout the pipe but less than atmospheric pressure
- D. same throughout the pipe but more than atmospheric pressure
Explanation: In an incompressible fluid (assuming the liquid is incompressible) flowing through a horizontal pipe, Bernoulli's principle applies.
Correct answer: lower where the diameter is large- A. Mass
- B. Energy
- C. Momentum
- D. All
Explanation: Bernoulli's equation is based on the conservation of energy along a streamline in a flowing fluid.
Correct answer: Energy- A. 4 times
- B. 16 times
- C. 1/4 times
- D. remain the same
Explanation: According to the equation of continuity, the rate of flow of a liquid is inversely proportional to the square of the radius of the tube.
Correct answer: 1/4 times- A. Decreases with age
- B. Increases with age
- C. Remains the same
- D. Cannot be predicted
Explanation: As a person ages, the blood vessels tend to lose elasticity and become less compliant.
Correct answer: Increases with age- A. 9.8 N
- B. 4.9 N
- C. 19.6 N
- D. 20 N
Explanation: The maximum dragging force on a sphere moving through a fluid is equal to its weight, which is 9.8 N in this case.
Correct answer: 9.8 N- A. laminar
- B. regular
- C. streamline
- D. turbulent
Explanation: Above the critical velocity, the fluid flow becomes turbulent. Turbulent flow is characterized by chaotic and irregular movement of fluidβ¦
Correct answer: turbulent- A. barometer
- B. sphygmomanometer
- C. venturi meter
- D. stethoscope
Explanation: A sphygmomanometer is the instrument used to measure blood pressure. It consists of an inflatable cuff that is wrapped around the upperβ¦
Correct answer: sphygmomanometer- A. equal to that of water
- B. 3 to 5 times that of water
- C. 2 to 3 times that of water
- D. 2 to 5 times that of water
Explanation: The high concentration of red blood cells in blood can increase its viscosity.
Correct answer: 2 to 5 times that of water- A. moves in different direction
- B. moves along the same path as
- C. slowly moves in one direction
- D. none of these
Explanation: Streamline flow (laminar flow): This type of flow is characterized by smooth, parallel layers of fluid particles moving with constantβ¦
Correct answer: moves along the same path as- A. 0
- B. high
- C. low
- D. constant
Explanation: Therefore, Bernoulli's principle explains why pressure is generally low in regions where the fluid speed is high and vice versa
Correct answer: high132. a two meter high tank full of water. A hole is made in the middle of tank. the speed of efflux is
- A. 4.9
- B. 9.8
- C. 4.42
- D. 3.75
Explanation: As hole is in the middle so the depth to be put in torricelli's theorem would be 1m.v = β(2 * 9.8 m/sΒ² * 1 m)v β β(19.6 mΒ²/sΒ²)v β 4.42 m/sβ¦
Correct answer: 4.42- A. 1000 liters
- B. 1200 liters
- C. 100 liters
- D. 2000 liters
Explanation: The work done by the pump is given by the formula:Work=PowerΓTimeIn this case, the power of the pump is given as 2 kW, and we need to findβ¦
Correct answer: 1200 liters- A. Maximum
- B. Minimum
- C. Zero
- D. Decreasing
Explanation: Terminal velocity is the constant speed that a freely falling object eventually reaches when the resistance of the medium (such as air orβ¦
Correct answer: Zero- A. Equation of continuity
- B. Bernoulli's theorem
- C. Torricelli's theorem
- D. Equation for compressible fluids
Explanation: The given equation is associated with Torricelli's Law, which states the speed (v) of efflux of a fluid from an orifice under theβ¦
Correct answer: Torricelli's theorem- A. Increase
- B. Decrease
- C. Remain constant.
- D. Doubles
Explanation: The relationship between temperature and viscosity can vary depending on the substance.
Correct answer: Decrease- A. Maximum
- B. Minimum
- C. Infinite
- D. Equal to what is in turbulent flow.
Explanation: In the case of streamlined (laminar) flow of liquid, the loss of energy is typically at a minimum.
Correct answer: Minimum- A. Bernoulli's equation
- B. Ventura relation
- C. Torricelli's theorem
- D. None
Explanation: The car engine operates based on the principles of thermodynamics and internal combustion, and it is not directly based on Bernoulli'sβ¦
Correct answer: None- A. Torricelli effect
- B. Bernoulli effect
- C. Venturi effect
- D. Doppler's effect
Explanation: Bernoulli's principle describes the decrease in pressure with an increase in fluid speed in a horizontal tube
Correct answer: Bernoulli effect- A. 591 m/s
- B. 461 m/s
- C. 396 m/s
- D. 372 m/s
Explanation: Correct. The average speed of oxygen molecules at S.T.P is approximately 461 m/s.In summary, the correct option is **b.
Correct answer: 461 m/s