281.  The height of water level in a tank above the centre of a circular hole 2.5 cm in diameter is 50 m. The velocity of water flowing through the hole, is
A. 31.1 m/sec
B. 31.2 m/sec
C. 31.3 in/sec
D. 31.4 in/sec.

---

282. Hydraulic coefficient of an orifice means the coefficient of
A. velocity
B. contraction
C. resistance
D. all the above.

---

283.  If Cv, Cc, Cd and Cr are the hydraulic coefficients of an orifice, then
A. Cd = C v. Ce
B. C = 1 + Co21Cd
C. Ce = Ce + Cd
D. C e = C eICd.

---

284. If vi and uz are the velocities of flow before and after sudden enlargement in a pipe, the head loss given by Carnot and Borda equation, is
A.(022 v12)126,
B. (a ? a2)2/2g
C. (02 ? v)2/2g
D. (01 + c2)212g.

---

285.  Apipe of 0.1 m2 cross sectional area suddenly enlarges to 0.3 in4 cross-sectional area. If the discharge of the pipe is 0.3 m3/sec, the head loss is
A. 2g m of water
B. g/2 m of water
C. lg m of water
D. m of water.

---

286.  In a short cylindercial external mouthpiece, the venacontracta occurs at a distance from the outlet of orifice equal to
A. diameter of the orifice
B. one-fourth the diameter of the orifice
C. one-third the diameter of the orifice
D. two-third the diameter of the orifice

---

287. The shape of fire hose nozzle is generally kept
A. divergent
B. convergent
C. convergent divergent
D. cylindrical.

---