Questions and answers for exam Preparation

MCQs

Total Questions : 3147 | Page 140 of 315 pages

Question 1391. 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

2A × √H₁/Cd × a × √(2g)
2A × √H₂/Cd × a × √(2g)
2A × (√H₁ - √H₂)/Cd × a × √(2g)
2A × (√H3/2 - √H3/2)/Cd × a × √(2g)

Discuss Question

Answer: Option C. -> 2A × (√H₁ - √H₂)/Cd × a × √(2g)
Answer: (c).2A × (√H₁ - √H₂)/Cd × a × √(2g)

Question 1392. The flow at critical depth in an open channel is called torrential flow.

Yes
No
Can't say
None of these

Discuss Question

Answer: Option B. -> No
Answer: (b).No

Question 1393. The power transmitted through the nozzle is maximum when the head lost due to friction in the pipe is __________ of the total supply head.

one-half
one-third
two-third
None of these

Discuss Question

Answer: Option B. -> one-third
Answer: (b).one-third

Question 1394. In case of flow through parallel pipes,

the head loss for all the pipes is same
the total discharge is equal to the sum of discharges in the various pipes
the total head loss is the sum of head losses in the various pipes
Both a and b

Discuss Question

Answer: Option D. -> Both a and b
Answer: (d).Both a and b

Question 1395. The torque required to overcome viscous resistance of a collar bearing is (where R1 and R2 = External and internal radius of collar)

(μπ²N/60t) × (R₁ - R₂)
(μπ²N/60t) × (R₁² - R₂²)
μπ²N/60t) × (R₁³ - R₂³)
(μπ²N/60t) × (R₁⁴ - R₂⁴)

Discuss Question

Answer: Option D. -> (μπ²N/60t) × (R₁⁴ - R₂⁴)
Answer: (d).(μπ²N/60t) × (R₁⁴ - R₂⁴)

Question 1396. The torque required to overcome viscous resistance of a footstep bearing is (where μ = Viscosity of the oil, N = Speed of the shaft, R = Radius of the shaft, and t = Thickness of the oil film)

μπ²NR/60t
μπ²NR²/60t
μπ²NR³/60t
μπ²NR⁴/60t

Discuss Question

Answer: Option D. -> μπ²NR⁴/60t
Answer: (d).μπ²NR⁴/60t

Question 1397. The dynamic viscosity of the liquid __________ with rise in temperature.

remain unaffected
increases
decreases
None of these

Discuss Question

Answer: Option C. -> decreases
Answer: (c).decreases

Question 1398. Coefficient of velocity is defined as the ratio of

actual velocity of jet at vena contracta to the theoretical velocity
area of jet at vena contracta to the area of orifice
actual discharge through an orifice to the theoretical discharge
none of the above

Discuss Question

Answer: Option A. -> actual velocity of jet at vena contracta to the theoretical velocity
Answer: (a).actual velocity of jet at vena contracta to the theoretical velocity

Question 1399. The mass of 2.5 m³ of a certain liquid is 2 tonnes. Its mass density is

200 kg/m³
400 kg/m³
600 kg/m³
800 kg/m³

Discuss Question

Answer: Option D. -> 800 kg/m³
Answer: (d).800 kg/m³

Question 1400. When a vertical wall is subjected to pressures due to liquid on both sides, the resultant pressure is the __________ of the two pressures.