Chapter 3 · MCQ Read Mode

Basic Water Resources Engineering

An ideal fluid, as a theoretical idealization, is characterized by:

A Newtonian fluid is defined by:

Specific weight (γ) of a fluid is related to mass density (ρ) by:

Kinematic viscosity (ν) is related to dynamic viscosity (μ) by:

Capillarity (capillary rise/depression) in a narrow tube results from:

Surface tension causes a liquid surface to behave like:

Cavitation occurs when local fluid pressure drops to or below:

A key damaging effect of cavitation on hydraulic machinery is:

Compressibility of a fluid is related to its bulk modulus of elasticity such that:

Specific gravity of a liquid is defined relative to which reference fluid?

Pascal's law states that pressure applied to an enclosed, incompressible fluid is:

The pressure-depth relationship in a static fluid of constant density is given by:

A U-tube manometer, compared to a simple piezometer tube, is generally used to measure:

The total pressure force on a submerged plane surface is calculated as:

The centre of pressure on an inclined/vertical submerged plane surface is located:

For a curved submerged surface, the vertical component of the resultant pressure force equals:

Archimedes' principle states that a submerged/floating body experiences a buoyant force equal to:

A floating body is considered stable when:

For a fully submerged body such as a submarine, stability depends on:

A pressure diagram for a submerged surface of constant depth-based linear pressure variation is typically:

Steady flow is characterized by:

Laminar flow is generally associated with:

The continuity equation for steady, incompressible flow through a pipe is expressed as:

The momentum equation, derived from Newton's second law, is primarily used to determine:

Bernoulli's equation, in its standard form along a streamline, states that which sum is constant?

Bernoulli's equation is derived under which key assumptions?

A venturi meter measures flow rate by relating flow to:

Compared to a venturi meter, an orifice meter generally causes:

A pitot tube measures local flow velocity based on:

Irrotational flow is defined as flow in which fluid particles:

The Reynolds number for pipe flow is calculated as:

Major (friction) head loss in a pipe is calculated using:

Minor (local) head losses at fittings, bends, and valves are generally expressed as:

The Hydraulic Grade Line (HGL) represents:

The Total Energy Line (TEL), compared to the HGL, is:

The Hardy Cross method is used to solve:

Water hammer in a pipe system is triggered by:

Unmitigated water hammer pressure surges can potentially cause:

Which of the following is a relief device used to mitigate water hammer effects?

Pipe design generally balances:

Hydraulic radius of an open channel section is defined as:

The Froude number for open channel flow is defined as:

Subcritical open channel flow (Fr < 1) is characterized by:

Specific energy in open channel flow is defined as:

For a given specific energy above the minimum, an open channel flow section generally has:

A hydraulic jump is best described as:

The depths before and after a hydraulic jump (sequent depths) are related using:

Gradually varied flow (GVF) profiles, such as M1/M2/M3, are classified based on:

A mobile boundary (alluvial) channel is characterized by:

The Shield diagram is used to assess:

The hydrologic cycle describes:

A water balance equation for a catchment generally accounts for:

A rating curve at a gauging station relates:

On a typical flood hydrograph, the rising limb, peak, and falling limb represent:

A unit hydrograph represents the direct runoff hydrograph resulting from:

A synthetic unit hydrograph is used when:

Flood frequency analysis typically involves fitting a probability distribution such as Gumbel or Log-Pearson Type III to:

The design flood for a hydraulic structure such as a spillway or bridge is determined based on:

Groundwater flow through an aquifer is fundamentally governed by:

A 'cone of depression' in groundwater hydrology refers to:

Two pipes, each of diameter d, converge to form a pipe of diameter D. What should be the relation between d and D so that flow velocity in the third pipe becomes double the velocity in each of the two pipes?

When pipes of the same material are connected in parallel, the total loss of head:

When three pipes are connected in series, which statement is true?

. Moody's diagram for estimating head loss was originally developed for:

The Moody's chart is a logarithmic chart plotted against Darcy-Weisbach friction factor and:

In the Moody diagram, ε/D is a parameter. What is represented by it?

For a fluid flow in a hydrodynamically smooth pipe, friction factor depends on:

The boundary is known as hydrodynamically smooth if ε/D ratio is:

The knocking sound in the pipe is due to:

The magnitude of water hammer depends upon:

The maximum vacuum created at the summit of the siphon pipe is equal to:

Which parameter determines the efficiency of a channel?

For the most economical channel section, which parameter should be minimum?

For a most economical rectangular channel of depth y and width B:

For a rectangular channel with the given dimensions, bed slope and Manning coefficient, the discharge is:

The discharge through a rectangular channel is maximum when:

Hydraulic radius of a wide rectangular channel is approximately:

Hydraulic radius of the most economical triangular channel:

The most economical and efficient section is:

For a hydraulically efficient trapezoidal section, hydraulic radius is:

In the most economical trapezoidal section, top width is:

Discharge through a trapezoidal channel is maximum when:

Hydraulic radius for the most economical trapezoidal section is:

At the vertex of a channel, the water level at the centre is:

Depth of flow changes over a short length of channel. It is:

Depth changes along the channel but does not change with time. This is:

A steady uniform flow occurs through:

Which is NOT a condition for uniform flow?

Open-channel flow becomes transitional when Reynolds number is:

For open-channel flow, the range around Re = 500–2000 is commonly treated as transitional.

Hydraulic gradient line for open-channel flow is:

Hydraulic gradient is equal to:

Condition for critical flow is:

In critical flow, velocity head is:

Find critical depth of a rectangular channel having width 3 m and discharge 15 m³/s.

Maximum velocity in an open channel occurs:

If water depth is less than critical depth, flow is:

When depth is greater than critical depth, velocity is:

Chezy's formula is used to determine:

For the same specific force, the two depths are called:

Alternate depths in open-channel flow are associated with:

The depth at which specific energy is minimum is called:

. A rectangular channel has width 5 m, discharge 10 m³/s and depth 2 m. Specific energy is:

In a specific-energy curve, the plot of pressure head is:

Specific-energy curve is a graph of ______ versus specific energy:

Specific energy for the most economical trapezoidal channel in the given problem is:

Which statement about specific energy is correct?

Energy per unit weight of water measured with respect to datum is:

Channel depth = 1.2 m and specific energy = 1.24 m. Find velocity.

Alternate depths have:

At critical depth, discharge is:

At critical depth, specific energy is:

Formula for sequent depth in a rectangular channel:

Sequent-depth ratio is 16.48. Find Froude number of supercritical stream

Sequent depth ratio = 16.48. Approximate Froude number

Sequent depths in a hydraulic jump are 0.25 m and 1.25 m. Energy loss:

For a given discharge, two depths having the same specific energy are:

For subcritical flow in an open channel, the most important control section for gradually varied flow profile is:

Rising water profile on the upstream side of a dam is called

Hydraulic jump can occur:

Hydraulic jump is a:

Rise of water level transforming unstable supercritical flow to stable subcritical flow is:

Hydraulic jump is classified based on:

For rectangular channels, hydraulic-jump length is approximately:

Oscillating hydraulic jump occurs when Froude number is:

Hydraulic jump is considered steady when:

Hydraulic jump for Froude number greater than 5.5 is:

Height of hydraulic jump in rapidly varied flow is:

Height of hydraulic jump is ______ of conjugate depth.

Froude number of a triangular channel with side slope 2H:1V is:

Critical-flow condition is:

Water cushion is used to:

If channel-bottom slope is greater than critical slope, it is:

A non-sustaining channel is one whose slope:

Supercritical flow occurs in:

When slope changes from mild to steep, the profile formed is:

In an M1 profile of gradually varied flow:

Whose equation is associated with bed-load transport rate?

Incipient motion means particles:

Tractive force in a mobile-boundary channel is:

Which is NOT a formation normally seen in an alluvial channel with sediment movement?

Basic mechanism behind sediment transport is:

If critical shear stress is τc, average shear stress required to move grains is:

Formula for tractive force at bottom of channel:

Curve obtained by plotting shear Reynolds number on x-axis and tractive force parameter on y-axis is:

In a Moody diagram, e/D represents:

Branch of science dealing with occurrence, circulation and distribution of Earth's water:

Hydrology helps in:

Area draining into a stream at a given location is called:

Average annual rainfall in Nepal is approximately:

All forms of water reaching Earth from atmosphere are called:

Interception losses are mainly due to:

Compared with a fan-shaped catchment, a fern-shaped catchment generally has:

Correct statement about stream length in fan-shaped and fern-shaped catchments:

Farm pond is used for:

Precipitation caused by lifting an air mass due to pressure difference is

Precipitation caused by upward movement of warmer air compared with surrounding air:

Cold-frontal precipitation generally occurs over:

Cold-frontal precipitation is formed because:

Standard rain-gauge height:

Symon's rain gauge is:

Commonly used recording rain gauge:

Which recording rain gauge does not produce a mass curve directly?

A rainfall hyetograph shows:

Instrument used to measure evaporation:

Evaporation depends on:

Chemical suitable for reducing evaporation from water surface:

Rain simulators are used for determination of:

Infiltration capacity depends upon:

Wind speed is measured with:

Mass curve of rainfall is a plot of:

Double-mass curve technique is used to:

Plot of cumulative discharge against time in chronological order is:

Total rainfall is 16 cm over 1200 km² during a 6-hour storm. Surface runoff is 1.2 × 10⁸ m³. Find runoff rate.

Rain gauges outside a catchment can be considered in:

The less accurate method for estimating average rainfall over an area is:

Best method for average annual precipitation in a catchment basin:

Thiessen polygon is:

Lines joining points having equal rainfall depth for a given duration are:

Most accurate method for average rainfall in a hilly catchment:

Isohyets are imaginary lines joining points having equal:

Instrument used to measure velocity of river water:

Surface runoff is the quantity of water:

The indirect method for discharge measurement is:

If the stage-discharge relationship at a gauging section is constant with time, the control is called:

To determine discharge from a stream rating curve, the required data are:

If a gauging section has shifting control due to backwater effects, then:

Backwater curve is caused if there is:

Water-surface elevation measured above a datum in a river is known as:

The curve obtained by plotting discharge versus stage is called:

Average mean velocity of a stream of depth h may be obtained by averaging current-meter readings at:

A triangular channel has top width 2.0 m and depth 0.9 m; velocities at 0.18 m and 0.72 m below the surface are 0.6 m/s and 0.4 m/s respectively; find discharge.

A stream is 10 m deep and velocities at depths 2 m and 8 m are 0.7 m/s and 0.3 m/s; discharge per unit width is:

As the duration of a unit hydrograph increases:

The ordinate of a unit hydrograph is obtained by dividing the ordinate of DRH by:

A hydrograph representing one unit of runoff from a rainfall of specified duration and distribution is called:

A unit hydrograph has one unit of:

A graph showing variation of discharge with time at a particular point of a stream is:

The shape of the recession limb of a hydrograph depends on:

Variation in peak discharge in a hydrograph is acceptable up to:

Variation in the hydrograph base is acceptable up to:

Point of inflection in a hydrograph represents the condition of:

The time required by rainfall to reach the outlet of a drainage basin is generally:

Time required for water to flow from the most remote point in a watershed outlet is called:

When a watershed changes from rural to urban, the effect of urbanization on the storm-runoff hydrograph is to:

A mean annual runoff of 1 m³/s from a catchment of 31.54 km² represents an effective rainfall of:

A triangular direct-runoff hydrograph has a time base of 80 hours and peak flow of 50 m³/s; catchment area is 144 km²; rainfall excess is:

If two 2-hour hydrographs are staggered by 2 hours and added graphically, the resulting hydrograph will be:

What happens to the probability of annual damage if the design flood is increased?

In the WECS/DHM method, the formula used for flood forecasting for a return period of 2 years is:

For estimating high floods in fan-shaped catchments, the formula used is:

Rational formula is applicable only to:

For annual flood series arranged in descending order, the return period for the magnitude listed at position m in N entries by Weibull formula is:

The probability that a 100-year flood may not occur during 50 years is:

A saturated earth formation that stores water and yields it in sufficient quantity is called:

A geological formation that is essentially impermeable to the flow of water is called:

The volume of water that can be extracted by gravity from a unit volume of aquifer material is called:

The quantity of water retained by soil against gravity is known as:

An ephemeral stream:

Groundwater table is observed by:

A substance which deforms continuously under shear stress is called:

When an external force is applied to a solid, it undergoes:

A fluid of volume 200 m³ weighs 1060 N. If acceleration due to gravity is 6.625 m/s², find its mass density.

If shear stress is 0.03 N/m² and velocity gradient is 0.15 s^-1, find the viscosity.

A fluid will undergo ______ under the action of shearing stress.

On increasing the temperature, the density of water ______.

On increasing the pressure, the density of the fluid ______.

The density of fluid at Earth's equator is ______ than at the pole.

The specific gravity of water at 20°C and 1 atmospheric pressure is ______.

If the volume of a liquid weighing 3000 kg is 4 cubic meters, then 0.75 is its ______.

The maximum density of water occurs at ______ Celsius.

The cohesion of the liquid molecules ______ with the rise in temperature.

Hooke's law for solid is analogous to ______.

Viscosity is defined as ______.

The SI unit of viscosity is ______.

What is the SI unit of kinematic viscosity?

Stoke is the unit of ______.

With increase in temperature, viscosity ______.

Viscosity of gases is mainly due to:

Viscosity of gases varies with temperature:

Kinematic viscosity of air is approximately how many times that of water at 20°C?

A fluid has kinematic viscosity 0.1 stokes. Its value in m²/s is:

Shear stress = 0.03 N/m² and velocity gradient = 0.15 s^-1. Find viscosity.

Dimension of kinematic viscosity is:

Dimensional formula of velocity gradient:

Dimensional formula of dynamic viscosity:

Falling water drops become spherical due to:

Surface tension is force:

Surface tension = 0.51 N/m and pressure inside a water drop is 0.05 N/cm² greater than outside. Find diameter.

Which has greater pressure difference for the same diameter?

A soap bubble has pressure difference 0.075 N/cm² and surface tension 0.075 N/m. Find diameter.

A liquid jet has diameter 5 cm and surface tension 0.075 N/m. Find pressure difference.

Find diameter of water drop if pressure difference = 0.05 N/cm² and surface tension = 0.075 N/m.

Rise of liquid in a small tube above the normal liquid level is called:

Capillary rise of water is:

For liquids, capillary rise/fall with increase in temperature:

If the same amount of liquid is poured into a tube of half the diameter, the rise becomes:

Capillary effect in a 7 mm mercury tube, σ = 0.51 N/m, θ = 130°, ρ = 13600 kg/m³:

In space, capillary rise of water in a tube would:

Mercury surface in an open glass tube is:

Cavitation occurs when pressure becomes:

Cavitation is caused mainly by:

When liquid pressure equals its vapor pressure, ______ occurs.

Variation of volume with pressure is called:

Bulk modulus of liquid:

Ideal flow of liquid obeys:

A fluid whose apparent viscosity increases with deformation rate is:

Fluid in which shear stress is proportional to shear strain rate is:

Vertical component of hydrostatic force on a curved surface equals:

For a static fluid, pressure:

According to Pascal's law, pressure at a point in static fluid is:

Pascal's law applies to:

Pressure at the same depth in narrow and broad containers is

According to Pascal's law, pressure at a point in a static fluid is:

Pressure at 1 m below water surface:

A pressure gauge measures:

Atmospheric pressure varies mainly with:

Atmospheric pressure is measured by:

Pressure below atmospheric pressure is called:

Absolute pressure equals:

Sensitivity of a simple manometer can be improved using:

Gas pressure in a pipe can be measured using:

Manometers are used to measure:

Piezometer is used to measure:

Device used to measure fluid pressure:

A mercury manometer is changed to water for the same pressure. The change in height difference is:

Bourdon gauge measures:

Best device for accurate measurement of high pressure:

Device used to measure pressure difference:

U-tube manometer is used to measure:

A tank contains water to depth h. Center of pressure is:

Pressure at any point in a non-moving fluid is called:

A rectangular lamina has width b, depth d, and its top is h below free surface. Centroid depth is:

Total pressure variation with depth for a submerged surface is:

In a stationary fluid, local pressure varies:

If a tank is moving horizontally, maximum pressure component on vertical walls occurs at:

For a completely filled cubical tank, ratio of hydrostatic force on base to one vertical wall is:

A cuboidal beaker is half full. If completely filled, hydrostatic force on vertical sides increases by:

Water depth = 0.5 m, oil of SG = 0.75 fills the remaining height to 1.5 m. Total force on the side:

Pressure in oil of SG = 0.85 is 4.9 N/cm². Find liquid height.

Isosceles triangular plate, base = 6 m, height = 6 m, base at oil surface. Center of pressure:

Circular gate diameter = 6 m, pressure = 25 N/cm², oil SG = 0.8. Force:

Center of pressure lies ______ the center of gravity for a vertical surface

For stable equilibrium of a completely submerged body:

Buoyant force is:

Buoyant force always acts:

Principle of flotation is based on:

Metacentre is:

If a disturbed body settles at a new position without returning to the original position, it is:

For a completely/partially immersed body to be stable, its weight should be distributed:

Relation between centroid G and center of pressure P:

A wooden block has length > breadth > height. For stable floating:

For a floating body at equilibrium, weight is:

Cylinder diameter = 4.5 m, height = 2.5 m, SG = 0.45. Find metacentric height.

A floating body is stable when metacentre is:

Positive metacentric height indicates:

A floating body displaces liquid whose ______ equals the body's weight.

Ice density = 900 kg/m³ and water density = 1000 kg/m³. Fraction of ice volume submerged:

A flow in which fluid properties and velocity change with time at a fixed location is:

If velocity, pressure and density change with time at a point, flow is:

If velocity, pressure and density do not change with time at a point, flow is:

If velocity changes along the direction of flow, it is:

If particle velocity varies from point to point and from instant to instant, the flow is:

Uniform flow occurs when:

Laminar flow occurs when particles:

For incompressible flow, Mach number should generally be less than:

Water flows through a frustum at constant rate. The flow is:

An imaginary line tangent to velocity direction is called:

A tangent drawn at a point on a fluid path gives:

Locus of different fluid particles passing through a fixed point is:

Flow in which paths of individual fluid particles cross is:

Path line is based on:

Continuity equation represents conservation of:

Bernoulli equation is derived from:

Venturimeter is used to measure:

In a venturimeter, divergent cone is:

Orientation of venturimeter during discharge measurement:

Minimum head loss occurs in:

Mouthpiece is used to measure:

If a Pitot tube faces downstream, liquid:

If a Pitot tube faces sideways:

When a water jet strikes a stationary vertical plate, the jet moves:

Momentum principle is not applicable to:

Jet velocity V strikes a plate moving with velocity u. Force is:

Force of water jet on stationary vertical plate:

At vena-contracta, jet area is minimum, so velocity is:

The minimum-area section of an orifice jet is called:

Relation among hydraulic coefficients:

Vena-contracta lies approximately:

Orifice used for low discharge:

Large orifice criterion:

Discharge through a small orifice:

An orifice is called large when water head is approximately:

Velocity of approach is:

If crest height is S, head is H, channel width is L and discharge is Q, velocity of approach:

Upper surface of a notch over which water flows is called:

V-notch gives maximum discharge when angle is:

Discharge through a V-notch varies as:

Head = 75 cm and measurement error = 0.15. Percentage error in discharge:

A weir whose crest is below downstream water level is:

Maximum discharge over a broad-crested weir occurs when middle water depth is:

A weir is broad-crested when crest width is: