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# Fluid Mechanics (201-220)

Updated: Apr 21, 2020

201. A normal shock wave occurs when the approaching flow is supersonic

202 Subsonic flow through a Converging duct Velocity increases and density decreases Subsonic flow through a Diverging duct Velocity decreases and pressure, density,temperature increase Supersonic flow through a Converging duct Density increases and velocity decreases Supersonic flow through a Diverging duct Velocity increases and pressure decreases

203.In steady, isothermal flow in long pipe lines, the significant value of Mach

number for determining trends in flow properties is 1/√K

204. A perfect gas at 27°C is heated at constant pressure till its volume is

doubled. The final temperature of the gas is 327°C

205. The number of revolutions of a current meter in 50 seconds were found to be 12 and 30 corresponding to the velocities of 0.25 and 0.46 m/sec. respectively. What velocity (in m/sec.) would be indicated by 50 revolutions of the current meter in one minute ? 0.60

206. A hydraulic turbine has a discharge of 5 m³/sec, when operating under a head of 20 m with a speed of 500 rpm. If it is to operate under a head of 15 m, for the same discharge, the rotational speed in rpm will approximately be 403

207. A fluid is a substance that can not remain at rest when subjected

to a shearing stress

208. The viscosity of a fluid varies with temperature

209. The locus of elevations that water will rise in a series of pitot tubes is called

the energy grade line

210. For a developed turbulent flow in a horizontal pipe, the pressure gradient.

varies linearly with distance

211. A dimensionless combination of surface tension σ, density ρ, diameter D and

velocity V is σ/ρV²D

212. The velocity potential function for a source varies with distance r as ln r

213. A streamlined body is defined as a body about which the flow separation is suppressed

214. If the velocity distribution is rectangular, the kinetic energy correction factor is

equal to unity

215. At room temperature, the dynamic and kinematic viscosity of water

are respectively greater than and less than that of air

216. One end of a two dimensional water tank has the shape of a quadrant of a circle of radius 2m. When the tank is full, the vertical component of the force per unit length on the curved surface will be 1000 π kgf

217. The mean velocities at two ends of a stream tube 10 cm apart are 2.5 m/s and 3 m/s. The convectional tangential acceleration mid-way is 13.75 m/s²

218. Which one of the following velocity fields represents a possible fluid flow ?

u = x; v = -y

219. A cylindrical vessel with a constant plane area of 1 m² is rotated about its

vertical axis such that the liquid inside the vessel is about to spill. If the height of the vessel is 2 m and the height of the paraboloid is 1m, then the volume (in m³)

of the liquid in the vessel will be 1.5

220.When a particular discharge is flowing in a horizontal pipe, a mercury-water U-tube manometer connected to the entrance and throat of a venturimeter fitted in the pipe recorded a deflection of 25 cm. If the same discharge flowed through the same pipe kept at an inclination of 45° to the horizontal, then the corresponding deflection by the U-tube manometer will be 25 cm