Select Page
Generic selectors
Exact matches only
Search in title
Search in content
Search in posts
Search in pages
Filter by Categories
nmims post
Objective Type Set
Online MCQ Assignment
Question Solution
Solved Question
Uncategorized

# Multiple choice question for engineering

## Set 1

1. Kinetic energy that results from the oscillation of water is called ________
a) Wave energy
b) Tidal energy
c) Ocean thermal energy
d) Hydro energy

Answer: a [Reason:] Kinetic energy that results from the oscillation of water is called wave energy. Wave energy is derived from wind energy, which derives in turn from solar energy. Wave energy can be much more concentrated than the solar energy.

2. How is height of wave determined?
a) By wind speed
b) By force of wave
c) By a immersion scale
d) By a floating device

Answer: a [Reason:] Wave height is determined by wind speed, the duration of time the wind has been blowing, fetch and by the depth and topography of the seafloor. A given wind speed has a matching practical limit over which time or distance will not produce larger waves.

3. What does oscillatory motion at ocean produce?
a) Microseisms
b) Froth
c) Disturbance of currents
d) Currents

Answer: a [Reason:] Oscillatory motion is highest at the surface and diminishes exponentially with depth. However, for near a reflecting coast, wave energy is also present as pressure oscillations at great depth, producing microseisms.

4. Waves are caused indirectly by ______
a) Wind energy
b) Solar energy
c) Geo-thermal energy
d) Wave energy

Answer: b [Reason:] Like the wind and OTEC, ocean and sea waves are caused indirectly by solar energy. Waves are caused by the wind, which in turn is caused by the uneven solar heating and subsequent cooling of the earth’s crust and the rotation of the earth.

5. Select the correct formula of potential energy in wave energy?
a) PE/A = 1/4ρa2 × g/gc
b) PE = 1/4ρa2 × g/gc
c) A/PE = 1/4ρa2 × g/gc
d) PE/A = 1/4ρa2 × g

Answer: a [Reason:] PE/A = 1/4ρa2 × g/gc is the correct formula for the potential energy of a wave. g = gravitational acceleration, m/s2 gc = conversion factor ρ = water density a = amplitude A = λL in J/m2.

6. Select the correct formula of kinetic energy of a wave?
a) KE/A = 1/4ρa2 × g/gc
b) KE = 1/4ρa2 × g/gc
c) KE = 1/4ρa2
d) KE/A = 1/4ρa2

Answer: a [Reason:] The correct formula for kinetic energy of a wave is KE/A = 1/4ρa2 × g/gc. g = gravitational acceleration, m/s2 gc = conversion factor ρ = water density a = amplitude A = λL in J/m2.

7. What are used to reduce to reduce the motion of floats?
a) Back pressure
b) Tubes
c) Damping fins
d) Anchor

Answer: c [Reason:] Damping fins are used to reduce the motion of the floats. The platform is stabilized within the water by four large underwater floatation tanks so that it is supported by the buoyancy forces. The floatation tank’s surfaces are wider in appearance and are flat.

8. From what material is the float (platform) made of _____________
a) Molded plastic
b) Thermocole
c) Stainless steel
d) Tubes

Answer: a [Reason:] The platform is made of molded plastic with s foamed plastic core to arrive at the required density and strength. It is also called float since it floats on the water. And it is in shape of cylinder with wide and flat bottom surface.

9. A _______ attached to the float moves up and down inside a cylinder?
a) chain
b) barrel
c) piston

Answer: c [Reason:] A piston attached to the float moves up and down inside a cylinder, fixed to the platform and is therefore relatively stationary. This piston cylinder arrangement is used as a reciprocating air compressor.

10. What type of energy is wave energy?
a) Non – conventional
b) Commercial
c) Non – renewable
d) Exhaustible

Answer: a [Reason:] Wave energy is free and non-conventional source of energy. Harnessing of energy by this method is relatively pollution free and because they remove energy from the waves, leaves the water in a relatively placid state in their wakes.

11. What is major disadvantage of wave energy?
a) It is not efficient enough
b) It is available only in ocean
c) The harnessing cost is more
d) Unstable during high wind pressures

Answer: b [Reason:] The major disadvantage of wave energy is that the energy is available on the ocean. The extraction equipment must be operated in a marine environment with all that implies in terms of maintenance, construction cost, life time and reliability.

12. Motion of water in a wave is primarily ________
a) Vertical
b) Horizontal
c) Linear
d) Opposite

Answer: a [Reason:] Wave motion is primarily horizontal but the motion of the water is vertical. Mechanical power is obtained by floats making use of the motion of water. The concept visualizes a large force that is driven up and down by the water within relatively stationary guides.

13. How many number of manifolds are part of a platform of floating device?
a) 1
b) 2
c) 3
d) 4

Answer: d [Reason:] There are four manifolds that are part of a platform. There are four large under water floatation tanks which stabilize the platform. Platform is supported by buoyancy forces and no vertical or horizontal displacement occurs due to wave action.

14. Which device uses the float which has two motions?
a) High level reservoir wave machine
b) Dolphin type wave generator
c) Hydraulic accumulator
d) Float wave power conversion device

Answer: b [Reason:] Dolphin type uses the float which has two motions. The first is a rolling motion about its own fulcrum with the connecting rod. Revolving movements are caused between the float and the connecting road. The other is nearly vertical or heaving motion about the connecting rod fulcrum.

15. In which wave machine instead of compressing air, the water itself is pressurized?
a) High level reservoir wave machine
b) Dolphin type wave generator
c) Hydraulic accumulator
d) Float wave power conversion device

Answer: c [Reason:] Hydraulic accumulator wave machines, instead of compressing air, the water itself is pressurized and stored in a high pressure accumulator or pumped to a high level reservoir, from which it flows through a water turbine electric generator.

## Set 2

1. What is the inherent weakness of all wind machines?
a) Their efficiencies
b) Requires powerful winds to make fan rotate
c) Their dependency on the wind speed
d) Cannot be easily repaired

Answer: c [Reason:] An inherent weakness of all wind machines are the strong dependence of the power produced on wheel diameter and wind speed, being proportional to turbine wheel area, i.e. to the square of its diameter and to the cube of wind velocity.

2. Why severe fluctuations in power are always undesirable in windmill?
a) Because they pose power oscillations problems
b) Damage of parts due to fluctuations
c) The efficiency of the plant will be reduced
d) Results in damage to the whole plant

Answer: a [Reason:] Severe fluctuations in power are always undesirable, because they pose power oscillation problems on the grid and severe strains on the windmill hardware. From an economic point of view, a windmill is designed to produce a rated power output corresponding to maximum, or near maximum, prevailing wind velocity at a given site would generate low powers, with full capacity of the turbine and electric generator unused much of time.

3. Maintenance of constant output at all wind speeds above rating is called _______
a) Numeric rating scale
b) Tenancy
c) Flat Rating
d) TRP

Answer: c [Reason:] More cost-effective design to a wind mill to produce rated power at less than the maximum prevailing wind velocity, using a smaller turbine and generator and to maintain a constant output at all wind speeds above rating. This is called flat rating.

4. A wind turbine designed too to come into operation at a minimum wind speed is called ______
a) Cut in velocity
b) Windward
c) Cut out velocity
d) Upwind location

Answer: a [Reason:] Due to several loss in efficiency and power at low wind velocities, a wind turbine is designed to come into operation at a minimum wind speed called the cut in velocity. Thus the wind turbine operates with variable load over a narrow range between cut in.

5. Why is wind turbine designed to stop operation at cut out velocity?
a) To protect wheel against damage
b) To make a quick stop in emergencies
c) To improve the efficiency

Answer: a [Reason:] To protect the turbine wheel against damage at very high wind velocities, it is designed to stop operation (such as feathering the blades) at cut out velocity. Thus the wind turbine operates at rated velocities and at constant power between the rated and cut out velocities and ceases the operation above the cut out velocity.

6. The fraction of time during a given period that the turbine is actually on line is called?
a) Availability factor
b) Flat rating
c) Cut in velocity
d) Cut out velocity

Answer: a [Reason:] The availability factor is defined as the fraction of time during a given period that the turbine is actually on line. The actual wind velocity at the propeller hub that determines the turbine power is usually higher.

7. Over load factor is also called as _____________
a) availability factor
b) plant operating factor
c) flat rating
d) cut out velocity

Answer: a [Reason:] The overall load factor, also called the plant operating factor and the plant capacity factor is the ratio of the total energy generated during a given period of time to the total rated generation capacity during the same period.

8. How many of windmills are there?
a) 2
b) 3
c) 4
d) 5

Answer: a [Reason:] There are two classes of windmill, horizontal axis and vertical axis. The vertical axis design was popular during the early development of the windmill. However, its inefficiency of operation let to the development of numerous horizontal axis designs.

9. Name the windmill which has four blades mounted on a central post.
a) Post mill
b) Smock mill
c) Tower mill
d) Fan mill

Answer: a [Reason:] The post mill has blades mounted on a central post. The horizontal shaft of the blade is connected to a large break wheel. The break wheel interacts with a gear system, called the wallower, which rotates a central, vertical shaft. This motion can then be used to power water pumping or grain grinding activities.

10. Name the type of windmill which consists of a sloping, horizontally weather boarded or thatched tower.
a) Post mill
b) Smock mill
c) Tower mill
d) Fan mill

Answer: b [Reason:] The smock mill is a type of windmill that consists of a sloping, horizontally weather boarded or thatched tower, usually with six or eight sides. It is topped with a roof or cap that rotates to bring the sails into the wind. It is similar to post mill. It is named so because of its appearance.

11. Which are further improvements on smock mill?
a) Post mill
b) Smock mill
c) Tower mill
d) Fan mill

Answer: c [Reason:] Tower mills are further improvements on smock mills. They have a rotating cap and permanent body, but this body is made of brick or stone. This fact makes it possible for the towers to be rounded. A round structure of it allows for large and taller towers.

12. Which type of windmills are been used for primary purposes?
a) Post mill
b) Smock mill
c) Tower mill
d) Fan mill

Answer: d [Reason:] The fan type windmill is specifically made for individuals. It is much smaller and used primarily for pumping water. It consists of a fixed tower (mast), a wheel and tail assembly (fan), a head assembly, and a pump.

## Set 3

1. How many years of minimum rainfall is required to design hydroelectric projects?
a) 10
b) 20
c) 25
d) 35

Answer: d [Reason:] In the design of hydro-electric projects, the rainfall record of nearly 35 years is required. This period is accepted as giving a reasonably accurate assessment of mean annual rainfall. Many times, it is not possible to wait many years for rainfall data and in such cases, shorter periods are accepted by design engineers with reserve and allowance is made for possible error.

2. There is requirement for wind shelter to reduce wind effect at rain gauge area.
a) True
b) False

Answer: a [Reason:] A wind shelter should be provided to reduce the effect of wind. The gauge should be erected on a level ground. The distance of the gauge from every object should not be less than twice the height of the object above the gauge.

3. What is the primary intention of rain gauging in hydro electric plant?
a) To determine force of storm
b) To determine monthly rainfall
c) To determine annual rainfall
d) To determine monthly and annual rainfall

Answer: d [Reason:] The primary intention of the rain gauging in hydroelectric work is to determine the monthly and annual rainfalls over catchment area. When the rain-gauging stations are more than one for a particular basin, calculation of average rainfall depending upon the area of the basin is done.

4. How many methods are used to determine the average rainfall depending upon area of basin in rain gauging?
a) 2
b) 3
c) 4
d) 5

Answer: b [Reason:] When there are more basins, three of the following methods are used to determine the average of rainfall depending upon the area of basin. They are Arithmetic mean method, Thiesson method and iso-hyetol method.

5. In which of the following rain gauging methods are the values of rainfalls of all stations added?
a) Arithmetic mean method
b) Thiesson method
c) Iso-hyetol method
d) Recording type

Answer: a [Reason:] In arithmetic mean method, the values of rainfalls of all the stations are added and the sum is divided by the number of gauging stations. This can be represented in the mathematical term as: ha = (h1+h2…….hn )/n = Ʃh/n.

6. Which among the following method is very accurate of rain gauging?
a) Arithmetic mean method
b) Thiesson method
c) Iso-hyetol method
d) Recording type

Answer: b [Reason:] Thiesson method is very accurate compared to other methods and is generally used when the catchment area lies between 500 to 5000km square. Assume that there are stations in the given basin names=d as 1,2,3,4,5,6,7, and 8. It is very important to divide the total basin area in such a way that each located station in the basin represents that area in the true.

7. Thiesson method is better result than arithmetic mean method because _________
a) It is shorter time consuming
b) Gives better detail about records
c) It is highly accurate
d) Small procedure

Answer: c [Reason:] The mean rainfall of the basin in thiesson method is given by: ha = (h1A1 + h2A2+ h3A3 + h4A4 + h5A5 + h6A6 + h7A7 + h8A8)/(A1+A2+A3+A4+A5+A6+A7+A8) This method gives better result than arithmetic mean method because it is very accurate and each point on a perpendicular bisector of the line joining the two gauging stations will be equidistant from both the stations. If one moves slightly this or that side of the bisector, the position will distinctly fall in the domain of that station of which ones position is now near.

8. In which of the following rain gauging method is contour joining the points of equal rainfall is done?
a) Arithmetic mean method
b) Thiesson method
c) Iso-hyetol method
d) Recording type

Answer: c [Reason:] In iso-hyetol method, contour joining the points of equal rainfall in the given catchment area is done. Iso-hyetes have following properties: Two different iso-hyetes do not cross each other. Each iso-hyete closes on itself. Iso-hyete of higher value indicates the higher rainfall.

9. Two successive Iso-hyetes in the basin drawing of catchment area are measured using _______
a) Planimeter
b) Manometer
c) Mass flow meter
d) Chronometer

Answer: a [Reason:] Generally interval of iso-hyete is one cm. after drawing the iso-hyetes; the area between two successive iso-hyetes is measured by using a Planimeter. The rest of the procedure of finding out the mean rainfall is similar to that described in the second method.

10. Iso-hyete method is commonly used for the basin area above 500sq.km?
a) True
b) False

Answer: a [Reason:] Iso-hyete method is commonly used for the basin above 500sq.km. The analysis of rainfall for power generation purposes is usually more concerned with dry years rather than wet years. For the assessment of storage requirements, it is often necessary to determine the driest period for which provision must be made.

11. Study of shape and features of earth surface is called __________
a) Vegetation
b) Geography
c) Anatomy
d) Topography

Answer: d [Reason:] The study of the shape and features of the surface of the earth is known as topology and it is a very important factor which is affecting the runoff and also the nature of catchment area depends on it.

12. Vegetation affects the runoff _____
a) True
b) False

Answer: a [Reason:] The transpiration and interception losses depend on the nature and extent of vegetation including crops. Vegetation, particularly of forest, has considerable effect upon the runoff. It consumes a proportion of the rainfall, causes interception losses and provides physical obstruction for runoff.

13. Rocky area gives higher runoff than sandy area ___________
a) True
b) False

Answer: a [Reason:] The geology of catchment area is of fundamental importance in the consideration of runoff. Rocky area gives higher runoff than sandy area. Even the evaporation losses increase with the increase in temperature.

14. The runoff calculated from the rainfall data available for sufficiently long period by multiplying with a coefficient is known as_________
a) Runoff coefficient
b) Rainfall coefficient
c) Topographic coefficient
d) Geo coefficient

Answer: a [Reason:] The runoff calculated from the rainfall data available for sufficiently long period by multiplying with a coefficient is known as runoff coefficient. The value of runoff coefficient is decided by considering all the factors which affect runoff.

15. The maximum rate of flow through the river is calculated by _________
a) Energy curves of flow
b) Force of flow
c) Pressure of flow

Answer: a [Reason:] The maximum rate of flow through the river is calculated by energy curves. Flood marks are also used to get the maximum flow rate. The following curves include Dickens formula, Inglis formula and ryve’s formula.

## Set 4

1. Constant head curves are also called as _______
b) Tail race curves
c) Main characteristic curves
d) Impeller curves

Answer: c [Reason:] Constant head curves are also called as main characteristic curves. It helps in determining the overall efficiency of the turbine by drawing curves with different set of parameters that play a major role in determining the performance of the turbine.

2. The speed of the turbine in a constant head curve is varied by __________
a) Temperature change
b) Reaction speed change
c) Changing the gate opening
d) Wheel speed change

Answer: c [Reason:] The speed of the turbine in a constant head curve is varied by maintaining a constant head. When we maintain a constant head, the speed of the turbine is varied by regulating the flow of fluid through a sluice gate.

3. Constant speed curves travel at constant speed when the value is equal to _______
a) 0
b) 1
c) 2
d) 3

Answer: b [Reason:] Constant speed curves detect the performance at different conditions. Characteristic curves of a turbine play an important role. It helps in determining the overall efficiency of the turbine by drawing curves with different set of parameters that play a major role in determining the performance of the turbine.

4. Power of a turbine is measured ______
a) Mechanically
b) Electrically
c) Chemically
d) Thermally

Answer: a [Reason:] Power of a turbine is measured mechanically by adjusting the flow of fluid using the percentage variations in a sluice gate. It helps in determining the overall efficiency of the turbine.

5. Which among the following is not a parameter to determine the efficiency of the turbine?
a) Unit speed
b) Unit power
c) Unit volume
d) Unit discharge

Answer: c [Reason:] Unit volume is not a parameter to determine the efficiency of the turbine. Power of a turbine is measured mechanically by adjusting the flow of fluid using the percentage variations in a sluice gate. It helps in determining the overall efficiency of the turbine.

6. Which among the following is not an important parameter to determine the performance of the turbine?
a) Speed
b) Discharge
d) Volume of tank

Answer: d [Reason:] Volume of tank is not an important parameter to determine the efficiency of the turbine. These are not drawn in the curves pertaining its efficiency.

7. Which among the following is not a type of curve?
a) Logarithimic curve
b) Straight curve
c) Pressure vs power
d) Efficiency vs speed

Answer: c [Reason:] Pressure vs power is not a characteristic curve that determines the overall efficiency of the turbine. This relation does not exist.

8. The inlet passage of water entry is controlled by ________
b) Gate
c) Tail race
d) Pump

Answer: b [Reason:] The inlet passage of water entry is controlled by the gate opening. The gate opening is an opening that sends only a percentage of fluid through the inlet passages for water to enter to the turbine.

9. Overall efficiency vs what is drawn to determine the turbine performance?
a) Unit Discharge
b) Unit speed
c) Unit power
d) Unit pressure

Answer: b [Reason:] One of the graphs to determine the performance of the turbine is overall efficiency vs the unit speed of the turbine. Unit speed is a speed of the fluid flow from inlet to the outlet of the turbine.

10. Constant discharge takes place due to _______
a) Unit Discharge
b) Unit speed
c) Unit power
d) Unit pressure

Answer: b [Reason:] Unit discharge is directly proportional to the discharge of fluid in the turbine. Unit discharge is the discharge through the turbine when the head of the turbine is unity. Unit discharge is one of the major unit quantities that determine the overall efficiency of the turbine.

11. All the characteristic curves are drawn with respect to __________
a) Unit Discharge
b) Unit speed
c) Unit power
d) Unit pressure

Answer: b [Reason:] All the characteristic curves that specify different parameters in a turbine are drawn with respect to its unit speed. Unit discharge, unit power and overall efficiency vs the unit speed is drawn.

12. Constant head curves are also called as _______
b) Tail race curves
c) Main characteristic curves
d) Impeller curves

Answer: c [Reason:] Constant head curves are also called as main characteristic curves. It helps in determining the overall efficiency of the turbine by drawing curves with different set of parameters that play a major role in determining the performance of the turbine.

13. In constant speed curves, the speed is kept a constant varying its head.
a) True
b) False

Answer: a [Reason:] Constant speed curves are also called as operating characteristic curves. It helps in determining the overall efficiency of the turbine by drawing curves with different set of parameters that play a major role in determining the performance of the turbine.

14. In all the characteristic curves, the overall efficiency is aimed at the maximum value.
a) True
b) False

Answer: a [Reason:] Yes, In all the characteristic curves, the overall efficiency is aimed at the maximum value. It helps in determining the overall efficiency of the turbine by drawing curves with different set of parameters that play a major role in determining the performance of the turbine.

15. Constant efficiency curves are plotted using _______
b) Constant speed curves
c) Main characteristic curves
d) Constant speed and constant head

Answer: d [Reason:] Constant efficiency curves are plotted using both Constant speed and constant head. Constant efficiency curves are also called as Muschel curves. It helps in determining the overall efficiency of the turbine by drawing curves with different set of parameters that play a major role in determining the performance of the turbine.

## Set 5

1. Kaplan turbine works on________
a) Electrical energy
b) Hydro energy
c) Thermal energy
d) Chemical energy

Answer: c [Reason:] Turbine is a vortex related device. It means turbulence. Turbine is a rotary mechanical device. Kaplan turbine is also called as a water turbine. It works when the blades are adjustable.

2. Kaplan turbine is an ______ reaction turbine
a) Inward flow
b) Outward flow
d) Axial

Answer: a [Reason:] Turbine extracts energy and converts it into useful work. Kaplan turbine is an inward flow reaction turbine. It is one of the most efficient turbines to drive electricity.

3. The Kaplan Turbine is an evolution of ________
a) Francis turbine
b) Pelton wheel
c) Parsons turbine
d) Curtis turbine

Answer: a [Reason:] The Kaplan Turbine is an evolution of Francis turbine. It was invented for an essential purpose. It allowed efficient power production in low head applications. Thus, making it better than Francis.

4. What is the dimension of thermal efficiency of a Kaplan turbine?
a) kg
b) m
c) kg/m
d) Dimensionless

Answer: d [Reason:] Thermal efficiency in thermodynamics is a dimensionless performance. It is a device that is used to measure thermal energy. It is mainly used in internal combustion engines.

5. A Kaplan turbine is used in ________
a) Turbomachinery
b) Pressure drag
c) Aerodynamics
d) Automobiles

Answer: a [Reason:] A Kaplan turbine is a turbomachinery. Turbine extracts energy from fluid flow and converts it into useful work. Turbine is a vortex related device. It means turbulence. Turbine is a rotary mechanical device.

6. The head of the Kaplan ranges from ______
a) 100 to 200 m
b) 250 to 300 m
c) 10 to 70 m
d) 0 m

Answer: c [Reason:] The head of the Kaplan ranges from 10 meters to 70 meters. A Kaplan turbine is a turbomachinery. Turbine extracts energy from fluid flow and converts it into useful work. Turbine is a vortex related device.

7. Nozzles in the Kaplan turbine move due to impact of ________
a) Water
b) Steam
d) Another nozzle

Answer: b [Reason:] Nozzle is moved due to the impact of steam. When the steam hits the nozzle, the pressure is decreased and the temperature is increased.

8. The power output of Kaplan turbine ranges from__________
a) 5 to 200 MW
b) 1000 to 2000 MW
c) 2000 to 3000 MW
d) 5000 and above

Answer: a [Reason:] The power output of Kaplan turbine ranges from 5 mega Watt to 200 mega Watt. It has got runner diameters which ranges from 2 meters to 11 meters. It varies from place to place.

9. Kaplan turbines rotates at a ________ rate
a) Increasing
b) Decreasing
c) Constant
d) Increasing and then decreasing

Answer: c [Reason:] Kaplan turbines rotates at a constant rate. A Kaplan turbine is a turbomachinery. Turbine extracts energy from fluid flow and converts it into useful work. Turbine is a vortex related device.

10. What type of turbine is Kaplan?
a) Impulse
b) Reaction
c) Energy
d) Hydro

Answer: b [Reason:] Kaplan turbine is a reaction turbine. It extracts energy from fluid flow and converts it into useful work. Kaplan turbine is a vortex related device.

11. Kaplan turbine is needed to improve ________
a) Increase Pressure
b) Decrease temperature
c) Change volume
d) Increase efficiency

Answer: d [Reason:] Kaplan turbine is needed to improve efficiencies at low speeds. When we arrange turbine blades in multiple stages. It plays an essential role in turbines.

12. Kaplan turbine is an ________ type turbine
a) Pressure
b) Inward flow
c) Outward flow
d) Velocity

Answer: b [Reason:] Kaplan turbine is an inward flow reaction turbine. It means that the working fluid changes its pressure as it moves through the turbine and gives up its energy.

13. The turbine does not have to be at the lowest point of water flow as long as the water in the draft tube is full.
a) True
b) False

Answer: a [Reason:] The turbine does not have to be at the lowest point of water flow as long as the water in the draft tube is full. A higher turbine located increases the suction and is imparted on the turbine blades by the draft tube.

14. The outlet of the Kaplan turbine is through _______
b) Moving pipeline
c) Draft tube
d) Pump