Hydraulics and Fluid Mechanics MCQs Archives

181. When the pressure intensity at a point is more than the local atmospheric pressure, then the difference of these two pressures is called

gauge pressure

absolute pressure

positive gauge pressure

vacuum pressure

✅ The correct answer is option C.

182. When an internal mouthpiece is running full, the discharge through the mouthpiece is twice the discharge when it is running free.

Correct

Incorrect

✅ The correct answer is option B.

183. The discharge through a channel of rectangular section will be maximum, if

its depth is twice the breadth

its breadth is twice the depth

its depth is thrice the breadth

its breadth is thrice

✅ The correct answer is option B.

184. The most economical section of a rectangular channel is one which has hydraulic mean depth or hydraulic radius equal to

half the depth

half the breadth

twice the depth

twice the breadth

✅ The correct answer is option A.

185. A differential manometer is used to measure

atmospheric pressure

pressure in pipes and channels

pressure in venturimeter

difference of pressure

✅ The correct answer is option D.

186. A fluid which obeys the Newton’s law of viscosity is termed as

real fluid

ideal fluid

newtonian fluid

non-newtonian fluid

✅ The correct answer is option C.

187. A vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. Which of the following statement is correct?

The pressure on the wall at the liquid level is minimum.

The pressure on the bottom of the wall is maximum.

The pressure on the wall at the liquid level is zero, and on the bottom of the wall is maximum

The pressure on the bo

✅ The correct answer is option C.

188. A tank of uniform cross-sectional area (A) containing liquid upto height (H1) has an orifice of cross-sectional area (a) at its bottom. The time required to bring the liquid level from H1 to H2 will be

✅ The correct answer is option C.

189. The ratio of the inertia force to the elastic force is called

Reynold’s number

Froude’s number

Weber’s number

Mach number

✅ The correct answer is option D.

190. The depth of centre of pressure (h) for a vertically immersed surface from the liquid surface is given by (where IG = Moment of inertia of the immersed surface about horizontal axis through its centre of gravity, A = Area of immersed surface, and x = Depth of centre of gravity of the immersed surface from the liquid surface)

✅ The correct answer is option D.