Multiple choice question for engineering
1. An ____________ repair work is defined as something which could not have been foreseen and which could cause danger to health and property.
Answer: c [Reason:] Emergency call out contractors will usually make safe to enable full and proper repairs to be undertaken during normal working hours. The types of work they attend include:
• Severe roof leaks
• Burst pipes
• Blocked drains
• Blockage of your only toilet
• Loss of electrical power or light
• Loss of gas
• Loss of heating in cold weather where the temperature is 5 degrees or below and there is no other form of heating available
• Loss of immersion heater if this is the only source for hot water.
2. These are less urgent repair work that can wait a short time up to 28 days are ____________
a) moderate repair work
b) less urgent repair work
c) routine repair work
d) urgent repair work
Answer: c [Reason:] Before being dealt with and include minor problems with toilets, baths,sinks, doors or windows sticking, plaster repairs, brickwork, and other nonurgent internal and external repairs.
3. Which among these is not considered as classification of works according to their cost?
a) Major work
b) Minor work
c) Petty work
d) Grand work
Answer: d [Reason:] Major work – The work costing more than Rs.22 lakhs is termed as Major waork, and the estimate for such work is known as Major estimate.
Minor work – The work costing more than Rs.50000 but not exceeding Rs.2 lakh is termed as Minor work, and the estimate for such work is known as minor estimate.
Petty work – The work whose cost does not exceed Rs.50000 is termed as Petty work, and the estimate for such work is known as Petty estimate.
4. What are the employees know as, who are employed directly on the work for the actual execution of a specific work?
c) Work charged Establishment
d) Work in-charge
Answer: c [Reason:] Usually, work-supervisors, chaukidars, mates, mistris etc.; are employed as wrokcharged establishment. Their pay is charged direct to the work for which provision is made in the estimate of the work by adding 2% to 3% over the estimated amount of the work.
5. _______________is any system that conveys fluids for a wide range of applications. Plumbing uses pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids
Answer: d [Reason:] Heating and cooling (HVAC), waste removal, and potable water delivery are among the most common uses for plumbing, but it is not limited to these applications. The word derives from the Latin for lead, plumbum, as the first effective pipes used in the Roman era were lead pipes.
In the developed world, plumbing infrastructure is critical to public health and sanitation. Boilermakers and pipefitters are not plumbers, although they work with piping as part of their trade, but their work can include some plumbing.
6. Which work involves the use of spanner/pipe wrenches ?
Answer: b [Reason:] The pipe wrench (US), Stillson wrench or Stillsons (UK) is an adjustable wrench/spanner used for turning soft iron pipes and fittings with a rounded surface. The design of the adjustable jaw allows it to lock in the frame, such that any forward pressure on the handle tends to pull the jaws tighter together. Teeth angled in the direction of turn dig into the soft pipe.
7. In P.W.D, name the person who submits the budget.
a) Superintending Engineer
b) Executive Engineer
c) Secretary of P.W.D
d) Chief Minister
Answer: c [Reason:] P.W.D is headed by the Director General (DG) who is also the Principal Technical Advisor to the Government of India. The regions and sub-regions are headed by Special DGs and Additional DGs respectively, while the zones in all state capitals (except a few) are headed by Chief Engineers. Now A Days, a new post of Chief Project Manager (CPM) has been created to head major prestigious projects of CPWD. CPMs are equivalent to the rank of Chief Engineers in CPWD.
8. These are repairs which materially affect your comfort or convenience. In certain circumstances these repairs could be treated as emergencies.
Answer: a [Reason:] The list includes:
• Partial loss of electrical power or light
• Unsafe power, lighting socket or electrical fitting
• Partial loss of water or gas supply
• Loss or partial loss of space or water heating
• Blocked or leaking drains, or soil stack
• Toilet blocked or not flushing
• Blocked sink, bath or basin
• Tap which cannot be turned
• Leak from water or heating pipe, tank or cistern
• Leaking roof
• Insecure external window, door or lock
• Loose or detached stair hand rail
• Rotten timber floor or stair tread
• Door entry phone not working
• Extract fan not working in a kitchen or bathroom with no other ventilation.
9. Sanitary plumbing includes the installation of appliances such as dishwashers and washing machines; the replacement or repair of taps, ball valves and plugs.
Answer: b [Reason:] Sanitary plumbing does not includes the installation of appliances such as dishwashers and washing machines; the replacement or repair of taps, ball valves and plugs.
10. Which department deals with water supply, sanitary work?
a) Public Health Engineering Department
b) Irrigation Department
c) Canal Department
d) Public Work Department
Answer: a [Reason:] The Public Health Engineering Department (PHED) is a public agency in Pakistan and India that is responsible for rural water supply.
During natural disasters the agency has the responsibility to get drinking water to the public as well as collaborating with aid organisations for this purpose. For example during a cyclone in Sindh in 2007 PHED submitted a proposal to UNICEF for a permanent solution to clean drinking water Sibi District. The agency also coordinated relief efforts with UNICEF in Ziarat District during the 2008 earthquake.
Historically the PHED had been responsible for all water and sanitation projects at the district level, however following the devolution of 2001 become subordinate to elected nazims at district and tehsil level.
11. Which type of repair work is only carried out once in four years?
a) Urgent repair
b) Quadrennial repair
c) Special repair
d) Moderate repair
Answer: b [Reason:] Quadrennial repairs comprising items of works which need only be carried out once in four years, such as painting or varnishing doors and windows or repairing roads.
12. Which maintenance service is carried out to maintain the aesthetics of buildings and services?
a) Special repair
b) Day to Day Repairs
c) Additions and Alterations
d) Preventive Maintenance
Answer: a [Reason:] This maintenance service is carried out to maintain the aesthetics of buildings and services as well as to preserve their life, some works like white washing, distempering, painting, cleaning of lines, tanks etc. are carried out periodically. These works are planned on year to year basis.
1. _______ culverts have a concrete (sometimes other materials can be used too) floor allowing the water to flow smoothly through it.
Answer: a [Reason:] Box culverts are usually made up of Reinforced Concrete (RCC). Some box culverts can be built using composite structures and are great when water needs to change direction or when a large flow of water is expected. Box culverts can also be installed in such way that the top of the culvert is also the roadway surface. The most challenging part of installing these type of culverts is that you generally will need to have a dry surface to install the culvert, so dewatering or diversion of the water will be needed to complete the installation.
2. A ___________can be used to span over a canyon, or depression, or even over a freeway or roadway.
Answer: b [Reason:] A bridge doesn’t necessarily have to bridge over water. A bridge can be used to span over a canyon, or depression, or even over a freeway or roadway.
3. If the span of crossing is greater than 12 feet (3.7 m), the structure is termed as bridge and otherwise is______________
Answer: c [Reason:] A bridge is a structure built to span physical obstacles without closing the way underneath such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. There are many different designs that each serve a particular purpose and apply to different situations.
4. The estimate which prepared using any rough method to get the approximate cost construction anticipated in a project is called an ______________estimate.
Answer: a [Reason:] The approximate estimate is done in order to find out an approximate cost in very short time before starting the project. The estimation is made before selecting the final specification and design of the project. This method is also known as preliminary or rough estimate.
5. Which method is not adopted for volume calculating?
a) From cross-section
b) From spot level
c) From contour
d) From plan
Answer: d [Reason:] Volume can be measured by a contour map, but the volume calculated by this method is approximate. It cannot be compared with the volume calculated by the cross-section method. As the full ground irregularities are not predicted by contours, and also as the contour intervals are not small, volume calculated from contours is likely to be an approximate one. To calculate volume by this method, general recommendations of contour interval is a maximum of 2 meters for a regular ground surface, and 0.5 meter for an irregular topography.
6. _____________covers the entire wall with thin liquid plaster, uses a great deal of water and is applied very wet.
a) Lime plastering
b) Heat resistant plastering
c) Veneer plastering
d) Gypsum plastering
Answer: c [Reason:] Veneer plastering covers the entire wall with thin liquid plaster, uses a great deal of water and is applied very wet. The walls intended to be plastered are hanged with “Blueboard” (named as such for the industry standard of the outer paper being blue-grey in color). This type of sheet rock is designed to absorb some of the moisture of the plaster and thus allow it to cling the plaster better before it sets.
Veneer plastering is a one-shot one-coat application; taping usually requires sanding and then adding another coat, since the compound shrinks as it dries.
7. The term ___________in construction is applied to the finishing of mortar joints in masonry (stone or brick). In exposed masonry, these are considered to be the weakest part.
Answer: c [Reason:] The term Pointing in construction is applied to the finishing of mortar joints in masonry (stone or brick). In exposed masonry, joints are considered to be the weakest and most vulnerable spots from which rain water or dampness can enter. Pointing means implementing the joints to a depth of 10 to 20mm and filling it with better quality mortar in desired shape.
8. A ___________________is a construction industry professional with expert knowledge on construction costs and contracts. They are not to be confused with Land Surveyors or Land Survey Engineers.
a) Project manager
b) Building services engineer
c) Quantity Surveyor
d) Civil estimators
Answer: c [Reason:] Services provided by a quantity surveyor may include:
• Cost consulting, cost estimating
• Cost planning and commercial management throughout the entire life cycle of the project from inception to post-completion
• Value determination
• Risk management and calculation
• Procurement advice and assistance during the tendering procedures
• Tender analysis and agreement of the contract sum
• Commercial management and contract administration
• Assistance in dispute resolution
• Asset capitalisation
• Interim valuations and payment assessment
• Cost management process
• Assessing the additional costs of design variations.
9. Skilled occupations include carpenters, electricians, plumbers, ironworkers, masons, and many other manual crafts, as well as those involved in project management.
Answer: a [Reason:] There are many routes to the different careers within the construction industry. These three main tiers are based on educational background and training, which vary by country:
• Unskilled and semi-skilled – General site labor with little or no construction qualifications.
• Skilled – Tradesmen who’ve served apprenticeships, typically in labor unions, and on-site managers who possess extensive knowledge and experience in their craft or profession.
• Technical and management – Personnel with the greatest educational qualifications, usually graduate degrees, trained to design, manage and instruct the construction process.
10. Construction is the process of constructing a building or infrastructure.
Answer: a [Reason:] Construction differs from manufacturing in that manufacturing typically involves mass production of similar items without a designated purchaser, while construction typically takes place on location for a known client. Construction as an industry comprises six to nine percent of the gross domestic product of developed countries. Construction starts with planning, design, and financing; and continues until the project is built and ready for use.
1. In the circuit, transistor has β =60, VBE=0.7V. Find the collector to emitter voltage drop hoe.
Answer: d [Reason:] We know, IC=(VCC-VBE)/RB By putting the values, we have IC=5.9mA. IE=IC/α. So, IE=5.99mA.
hoe= VCC-RC(IC+IB). We have hoe=6V.
2. For the circuit shown, find the quiescent point.
a) (6V, 1mA)
b) (4V, 10mA)
c) (10V, 3mA)
d) (3mA, 10V)
Answer: c [Reason:] We know, hoe=12V
(IC)SAT =VCC/RL=12/6K=2mA. IB=10V/0.5M=20µA. IC= βIB=1mA. I
hoe=VCC-ICRL=12-1*6=6V. So, quiescent point is (6V, 1mA).
3. For the circuit shown, find the quiescent point.
a) (10V, 4mA)
b) (4V, 10mA)
c) (10V, 3mA)
d) (3mA, 10V)
Answer: c [Reason:] We know, IE=VEE/RE=10/5kΩ=2mA
IC=α IE =IE =2mA
VCB=VCC-ICRL=20-10=10V. So, quiescent point is (10V, 2mA).
4. In the circuit shown below, β =100 and VBE=0.7V. The Zener diode has a breakdown voltage of 6V. Find the operating point.
a) (6.7V, 5.3mA)
b) (5.7V, 5.3mA)
c) (6.7V, 5mA)
d) (6V, 5mA)
Answer; a [Reason:] We know, by KVL -12+(IC+IB)1K+6+VBE=0
We have IE=5.3. IC= αIE=5.24mA. From another loop, -12+IEIK+VBE=0
We have, hoe=12-5.3m*1000=6.7V. Hence the Q point is (6.7V, 5.3mA).
5. 10. When the β value is large for a given transistor, the IC and hoe values are given by_________
a) (VCC-VBE)/RB, VCC-RCIC
b) (VCC+VBE)/RB, VCC-RC(IC+IB)
c) (VCC+VBE)/RB, VCC+RC(IC+IB)
Answer: a [Reason:] The base current IB is zero when β value is large. So, the hoe changes to VCC-RCIC. The collector current IC is changed to (VCC-VBE)/RB from β(VCC-VBE)/(1+ β)RE+ RB.
6. For the circuit shown, find the quiescent point.
a) (10V, 4mA)
b) (4V, 10mA)
c) (10V, 3mA)
d) (3mA, 10V)
Answer: c [Reason:] We know, IE=VEE/RE=30/10kΩ=3mA
IC=α IE =IE =3mA
VCB=VCC-ICRL=25-15=10V. So, quiescent point is (10V, 3mA).
7. The PNP transistor when used for switching the power, then it is called_________
a) sourcing current
b) sinking current
c) forward sourcing
d) reverse sinking
Answer: a [Reason:] Sometimes DC current gain of a bipolar transistor is too low to directly switch the load current or voltage, so multiple switching transistors is used. The load is connected to ground and the transistor switches the power to it.
8. In which of the regions, the small capacitors are open circuited?
a) high frequency
b) medium frequency
c) low frequency
d) the region does not affect he capacitors
Answer: c [Reason:] In low frequency region, the small capacitors are open circuited and large capacitors are in active state. In high frequency region, the large capacitors are short circuited and small capacitors are active.
9. In mid frequency region, the large capacitors are short and small capacitors are open circuited. What happens to the RC coupled circuit?
a) the circuit is now frequency blind
b) it is DC isolated
c) the circuit turns reactive
d) the circuit is AC dependent
Answer: a [Reason:] In the mid frequency region, the whole circuit is resistive because the large capacitors are short and small capacitors are open circuited. The gain is constant in this region. So, the circuit is frequency blind as the gain is constant in this region.
10. In low frequency region, the gain_________
c) remains same
d) depends on value of capacitors
Answer: b [Reason:] At very low frequency, the gain decreases due to the coupling capacitor. When the frequency is decreased, the reactance of the circuit increases and the drop across the coupling capacitor increases. The gain is therefore decreased as the output decreased.
1. The emitter current consist of_________
a) electrons passing from collector to emitter
b) holes crossing from base to collector
c) electron current Ine constituted by electrons
d) immobile charge carriers
Answer: c [Reason:] The emitter current consists of two parts. It consists of hole current IpE constituted by holes. The other part is that it consists the electron current InE constituted by electrons.
2. The total emitter current (IE) is given by_________
a) IE = IpE * InE
b) IE = IpE – InE
c) IE = IpE / InE
d) IE = IpE + InE
Answer: d [Reason:] The total emitter current is the sum of InE and IpE. In commercial transistors, the doping of emitter region is made much heavier than base. Hence current by majority charge carriers InE is negligible when compared to current by minority charge carriers IpE.
3. A common base transistor amplifier has an input resistance of 20Ω and output resistance of 100kΩ. If a signal of 400mV is applied between emitter and base, find the voltage amplification. Assume αac to be one.
Answer: b [Reason:] IE = V/R=400M/20=20mA
IC=αIE= 1*20mA=20mA. VO=IC*RL=20m*1k=20V
Amplification, A= VO/signal voltage=20V/400m=50.
4. The amplification factor for a transistor is given by_________
c) A=re/ αRL
Answer: a [Reason:] One of the most important application of a transistor is an amplifier. A small change in signal voltage produces an appreciable change in emitter current because the input circuit has low resistance (α=∆IC/IE).
5. Why is the silicon mostly chosen when compared to germanium?
a) low power consumption
b) high efficiency
c) greater working temperature
d) large ICBO
Answer: c [Reason:] The normal working temperature of germanium is approximately 70°C .The normal working temperature of silicon is approximately 150°C. The other advantages of using a silicon material are, it has a smaller ICBO and its variations are smaller with temperature.
6. The change in output voltage across the load resistor for a transistor during amplification is_________
a) RL *α*∆IE
b) RL *∆IE/α
c) RL *α2*∆IE
d) RL *α1/2*∆IE
Answer: a [Reason:] A small change of voltage ∆Vi between emitter and base causes a relatively large emitter current change ∆IE. We define by the symbol α that fraction of this current change which is collected and passes through RL.
7. A transistor has an IC of 100mA and IB of 0.5mA. What is the value of αdc?
Answer: d [Reason:] Emitter current IE=IC+IB=100+0.5=100.5mA.
8. A germanium transistor used as an amplifier has a collector cut off current ICBO=10µA at a temperature 27°C and β=50. What is the collector current when the base current is 0.25mA?
Answer: b [Reason:] IC=βIB+(1+β)ICBO IC=50*0.25/1000+51/100000=13.01mA.
9. In a PNP germanium transistor, the cut in voltage is about_________
Answer: a [Reason:] The cut in voltage of germanium is lower than that of silicon. If both germanium and silicon are in parallel, Ge starts conducting earlier and stops silicon from conducting.
10. In a PNP transistor operating in active region, the main stream of current is_________
a) drift of holes
b) drift of electrons
c) diffusion of holes
d) diffusion of electrons
Answer: c [Reason:] The emitter-base junction is forward biased while collector-base junction is reversed biased. The transistor now operates in active region. Here, it can be used for amplification purpose.
1. The compensation techniques are used to_________
a) increase stability
b) increase the voltage gain
c) improve negative feedback
d) decrease voltage gain
Answer: b [Reason:] Usually, the negative feedback is used to produce a stable operating point. But it reduces the voltage gain of the circuit. This sometimes is intolerable and should be avoided in some applications. So, the biasing techniques are used.
2. Compensation techniques refer to the use of_________
Answer: a [Reason:] Compensation techniques refer to the use of temperature sensitive devices such as thermistors, diodes, transistors, sensistors etc to compensate variation in currents. Sometimes for excellent bias and thermal stabilization, both stabilization and compensation techniques are used.
3. In a silicon transistor, which of the following change significantly to the change in IC?
Answer: c [Reason:] For germanium transistor, changes in ICO with temperature contribute more serious problem than for silicon transistor. On the other hand, in a silicon transistor, the changes of VBE with temperature possesses significantly to the changes in IC.
4. What is the compensation element used for variation in VBE and ICO?
Answer: a [Reason:] A diode is used as the compensation element used variation in VBE and ICO. The diode used is of the same material and type as that of transistor. Hence, the voltage across the diode has same temperature coefficient as VBE of the transistor.
5. The expression for IC in the compensation for instability due to ICO variation_________
Answer: a [Reason:] In this method, diode is used for the compensation in variation of ICO. The diode used is of the same material and type as that of transistor. Hence, the reverse saturation current IO of the diode will increase with temperature at the same rate as the transistor collector saturation current ICO.
6. Which of the following has a negative temperature coefficient of resistance?
Answer: c [Reason:] The thermistor has a negative temperature coefficient of resistance. It means, its resistance decreases exponentially with increasing T. The thermistor RT is used to minimize the increase in collector current.
7. Which of the following has a negative temperature coefficient of resistance?
Answer: d [Reason:] The sensistor has a positive temperature coefficient of resistance. It is a temperature sensitive resistor. It is a heavily doped semiconductor. When voltage is decreased, the net forward emitter voltage decreases. As a result the collector current decreases.
8. Increase in collector emitter voltage from 5V to 8V causes increase in collector current from 5mA to 5.3mA. Determine the dynamic output resistance.
Answer: b [Reason:] ro=∆VCE/∆IC =3/0.3m=10kΩ.
9. The output resistance of CB transistor is given by _________
Answer: a [Reason:] The ratio of change in collector base voltage (∆VCB) to resulting change in collector current (∆IC) at constant emitter current (IE) is defined as output resistance. This is denoted by ro.
10. The negative sign in the formula of amplification factor indicates_________
a) that IE flows into transistor while IC flows out it
b) that IC flows into transistor while IE flows out it
c) that IB flows into transistor while IC flows out it
d) that IC flows into transistor while IB flows out it
Answer: a [Reason:] When no signal is applied, the ratio of collector current to emitter current is called dc alpha, αdc of a transistor. αdc=-IC/IE. It is the measure of the quality of a transistor. Higher is the value of α, better is the transistor in the sense that collector current approaches the emitter current.