Question Bank • QB_EXP_SWCE_DYN_010 NAT • 2 Marks

Section 4: Soil and Water Conservation Engineering

Dynamics of Flow & Bernoulli Equation

Subtopic: Venturimeter pressure differential

Question Statement:

Water flows through a horizontal pipe of diameter $20\text{ cm}$ tapering to $10\text{ cm}$ at a rate of $0.050\text{ m}^3/\text{s}$. Neglecting frictional losses, the pressure drop between the inlet and throat is ________ $\text{kPa}$ (round off to two decimal places).

Answer Key:

19.00

Step-by-Step Solution & Explanation

From continuity: $A_1 = \frac{\pi}{4} (0.20)^2 = 0.03142\text{ m}^2 \implies v_1 = \frac{0.05}{A_1} = 1.592\text{ m/s}$ $A_2 = \frac{\pi}{4} (0.10)^2 = 0.00785\text{ m}^2 \implies v_2 = \frac{0.05}{A_2} = 6.366\text{ m/s}$ Applying Bernoulli's equation for horizontal pipe ($z_1 = z_2$): $P_1 - P_2 = \frac{1}{2} \rho (v_2^2 - v_1^2) = \frac{1000}{2} (6.366^2 - 1.592^2) = 19000.0\text{ Pa} = 19.00\text{ kPa}$
← Previous (QB_EXP_SWCE_DYN_007) Next (QB_EXP_SWCE_DYN_013) →

Practice In Authentic CBT Exam Interface

Test your skills under authentic timed conditions with live scoring and AIR percentile ranking.

Launch CBT Mock Test