UPDA SET 4

Questions and Answers

A series of fuel cells is connected to produce a no-load voltage of 230V at a rated voltage of 300V the cells provide 2.0 MW to a DC-AC converter. Assuming the cell van be modelled as a standard battery, what is the total internal resistance of the fuel cells

0.003 (correct)

0.05

0.0001

What is the insulation voltage level designed for the military marine system?

√2) A

(1 / √3) A

√3) A (correct)

The selected collector supply voltage is 12V. The transistor must be on for pulses of 150μA or greater only, what is the required value of the load resistance?

200Ω

300Ω

400Ω (correct)

600Ω

What is the maximum allowable size of the over-current device normally allowed to protect an AWG #12 THHW condu temperature of 550C? Only standard size over current device are available.

20A Signup and view all the answers

A single-phase transformer rated 100/7.2kV has an impedance of 10.0% during a factory short circuit test done at rated current the voltage the HV terminals will be most nearly:

10 Signup and view all the answers

A radio station transmits 50kW with a directive gain of 105. What is the power density 10km from the radiating antenna?

0.060 mW/m2 Signup and view all the answers

The SCADA system configuration uses input from an instrument CT with ratio of 100:5. the transducer supplying the SCADA has a full-scale AC current value of 2.5A. What is most nearly the maximum current in the primary side of the CT?

50 A Signup and view all the answers

What is HRC fuse?

High Rupturing Capacity Signup and view all the answers

Which of the following describes the leakage flux?

A flux outside the core Signup and view all the answers

For forward biasing

Anode 5V cathode 3V Signup and view all the answers

Which of the following parallel resistance will have the highest value of the equivalent resistance?

Two 500 kOhm resistors Signup and view all the answers

In the 3-phase system, the neutral is:

Abnormal return path for the current Signup and view all the answers

On the question above, what is the minimum diode power rating that can be used?

150 Signup and view all the answers

Which of the following characteristics is not typical of a project manager:

Possesses in depth technical knowledge Signup and view all the answers

Synchronous speed for motor 1200 RPM, 100Hz. Calculate number of poles?

P = 10 Signup and view all the answers

The CPU architecture shown in the figure below is best described as:

Harvard architecture Signup and view all the answers

While machine in operation, the slip of the synchronous machine is:

Zero Signup and view all the answers

A room with a floor area of 50ft x 30ft and a ceiling height of 10ft has luminaries suspended 2ft from the ceiling. Assuming a working plane of 30in and a required illumination level of 50fc, the net luminous flux (lumens) using fixtures with a coefficient of utilization of 0.78 is most nearly:

96000 Signup and view all the answers

Block plot shown below, what type?

Band stop filter Signup and view all the answers

In HDL Based digital systems the arithmetic multiplication function is difficult to synthesize. Design solution to this challenge do not include:

Hardware intensive simultaneous generation of partial products Signup and view all the answers

Intersymbol interface is eliminated by applying which of the following?

Nyquist Criterion Signup and view all the answers

Which is liquid in the following substances?

Hg Signup and view all the answers

Which of the following is based on Ohm’s Law?

Current Signup and view all the answers

Harmonic currents present in a power system may cause:

All of the above Signup and view all the answers

How can we convert in to cm?

Multiply by 2.54 Signup and view all the answers

A differential relay designed to protect a zone of the distribution system, uses current transformer (CTs) connected to annually CTs. The auxiliary CTs must match both the phase shift and the ratio of the differential relays CTs if the values do not match. Which of the following is the least likely outcome?

The trip could occur only when the CTs are wired in parallel Signup and view all the answers

A biomedical signal is sampled at 128Hz, no anti-aliasing fiber is used. Spectral analysis on the sampled data shows strong sit. The most likely source of the 58 Hz component is:

70 Hz source in the original signal Signup and view all the answers

A system with an initial cost of 90000 dollars has an operating cost of 2.50 dollars per hour and is operated 16hr/day for 300 days/year. After 10 years, the system has salvage value of 10000 dollars. Assuming the interest rate is constant at 10% the total analyzed cost over the 10-year life is most nearly

$26000 Signup and view all the answers

Of the following engineering discipline which would be best suited to manage the construction of a natural gas pipeline?

Mechanical Engineer Signup and view all the answers

When an activity network is developed by using forward and backward pass we can find out:

A, B, C and D are all correct Signup and view all the answers

Two tower antennas with height of 90 meter. What is the maximum distance between them for good communication

40 km Signup and view all the answers

Why steel is used in concert structure because:

temperature expansion coefficient is same with cement (concrete Signup and view all the answers

An engineer is offered some additional gifts and services in exchange for using superior materials on a remodeling project. This was not detailed in the contract. He should:

Reject the offer Signup and view all the answers

You are a project manager for a company that supplies parts to the government. Part of your budget plan shows an average can reduce move units. What theory that describes the rationale for the budget planning?

Economics of Scale Theory Signup and view all the answers

The extensive use of gypsum wall board in residential, commercial and industrial construction items from all the following is a gypsum board characteristic except:

Recycle ability or can be recycled Signup and view all the answers

Which of the following is not considered to be a characteristic of a project?

only for internal use Signup and view all the answers

The equivalent circuit of induction machine at no load is the same as that of the transformer but with:

Short circuited secondary Signup and view all the answers

The interdisciplinary nature of engineering has implications for the appropriateness of specialization. Which of the following is correct?

Most engineers will wish to specialize, but all engineers must be able to work effectively alongside others with complementary skills Signup and view all the answers

In a typical computer architecture, the minimum set of registers necessary for general operation will include:

Accumulator, instruction register, memory address register, memory buffer register, program counter Signup and view all the answers

The electric flux passing out through a closed surface is equal to:

The total charge enclosed by the surface Signup and view all the answers

A basic Time Domain Reflectometer (TDR) system is used with an oscilloscope to display the waveform at the input end of a line in a Non-Return Zero (NRZ) digital system. A 1000m cable is terminated with a short circuit at the far end. The first reflected wave appears 9.43μs after the incident wave. The actual velocity in the cable divided by the speed of light is:

0.71 Signup and view all the answers

The maximum power in a synchronous machine is obtained when the load angle is:

90 Signup and view all the answers

Increase water cement ratio in concrete mix

Results decrease strength Signup and view all the answers

The voltage waveform generated by an alternator having 4 poles and rotating at 750 RPM will have a frequency of:

25 Hz Signup and view all the answers

Which of the following Braking system is used in the induction motor?

All of the Above Signup and view all the answers

Induction motor running at synchronous speed, the torque will be:

0 Signup and view all the answers

The noise margins of an inverter with VOH=3V, VH=2V, VOL=0.5V, VIL=0.8V is:

NMH=1V, NML=0.3V Signup and view all the answers

Which of the following situations required a change order?

All of the above Signup and view all the answers

What is the maximum phase to phase voltage for induction motor in the figure?

480V Signup and view all the answers

3 Phase balanced system with Irms = 60A and 3rd harmonic phase current of 3A. What will be the neutral current?

9A Signup and view all the answers

In Ohms Law current is related to:

Voltage Signup and view all the answers

____________ activities must be completed immediately before a particular activity.

Predecessor Signup and view all the answers

In the 3-phase system, the neutral is:

Abnormal return path for the current Signup and view all the answers

Value engineering has the purpose of:

Achieve the project outcomes with the least cost Signup and view all the answers

Your boss has just approved the initiation of a project to celebrate Qatar National Day. Sadia has been assigned the project manager as should be:

Work on the project scope Signup and view all the answers

Field programmable gate arrays (FPGAs) and other array logic devices normally contain numerous flip-flops. These flip-flops are generally or the type:

D Signup and view all the answers

A discrete silicon semiconductor diode is forward biased at 0.75V, what is the approximate current?

2.0 mA Signup and view all the answers

In general, when comparing BJT and MOSFET transistors, three main differences

The device that depends more on geometry (width, Length, etc.) is BJT Signup and view all the answers

The motor used in travelling crane is:

Slip Ring AC Induction Motor Signup and view all the answers

In 50hz induction machine, if the no load speed is 2900 RPM, the slip frequency is:

1.67 Hz Signup and view all the answers

Changing in the excitation in grid having an alternator connected to it will having the following effect:

Change in reactive component of load Signup and view all the answers

Which of the following is based on Ohm’s Law?

Current Signup and view all the answers

What is the bond for attraction of water molecule?

Covalent Bond Signup and view all the answers

If the rotor is in standstill position, what is slip?

One Signup and view all the answers

architect visits the site and found out the gypsum installation ongoing is of very low grade, what immediate action should he take?

Stop the work Signup and view all the answers

If the motor is running with very heavy load, suddenly the mechanical load is reduced to zero, what will be the affect at the motor?

Motor will first move above synchronous speed and later stay just below synchronous speed. Signup and view all the answers

What is the theory of utilitarianism?

Work with global utilization – happily – maintain it. Signup and view all the answers

What would an initial investment of 1 million QR be after 5 years if the APR = 9% accumulated monthly?

1565681 QR Signup and view all the answers

Favorable exchange ratedollowing is not opportunity to do the project?

Favorable exchange rated Signup and view all the answers

Which of the following junction nodes are forward biased?

Anode = +5V, Cathode = +3V Signup and view all the answers

Hysteresis losses appears:

In magnetic material using AC supply. Signup and view all the answers

100 resistors of 100 ohm each are connected in parallel. Their equivalent resistance will be:

1 ohm Signup and view all the answers

Cut-off frequency in transistor is defined by:

External Capacitor Signup and view all the answers

Major factor to be considered while designing distribution system:

Reliability Signup and view all the answers

An over excited alternator is operating at:

lagging power factor Signup and view all the answers

Which one of the following is not an insulating material?

Porcelain Signup and view all the answers

The starting capacitor of a single phase motor is

Electrolytic type Signup and view all the answers

What is the role of ABET (Accreditation Board for Engineering & Technology)

Accreditation of Engineering Programs Signup and view all the answers

What does the power factor stands for

Cosine of the angle between voltage and current Signup and view all the answers

Strain Unit

Dimensionless Signup and view all the answers

What is the function of the barometer?

Measure the atmospheric pressure Signup and view all the answers

Which of the following is not linear regression model?

Y = a + X1 + bX22 Signup and view all the answers

In which of the following stages are you more likely to find status reports, many changes and the creation of forecasts?

Executing Signup and view all the answers

Out of the following, which is the best example of a project?

Studying till getting a graduate degree Signup and view all the answers

Which OP-AMP circuit uses resistance in series and capacitance in feedback

Integrator Signup and view all the answers

Intersecting point for WBS and OBS

Cost account Signup and view all the answers

The final step in the definition of a work breakdown structure is to

Assign codes for each activity of the work package Signup and view all the answers

What is the least instructive solution to connect hijacking?

Physical security of the communication link Signup and view all the answers

A 10MVA generator has power factor 0.866 lagging, the reactive power produced will be

5 MVA Signup and view all the answers

Permanent magnet has a relative permeability that is __________ magnetic material:

Higher than Signup and view all the answers

For a transformer to be tested at full load conditions but consuming only losses from the main, we do

back to back test Signup and view all the answers

A 400V/100V, 10KVA two winding transformer is reconnected as an auto transformer across suitable voltage source. The maximum rating of such an arrangement could be

50KVA Signup and view all the answers

A single-phase, 2,200/200 V transformer takes 1 A at the HT side or no load at a power factor of 0.385 lagging. The iron losses are

77 W Signup and view all the answers

Neglecting resistance, at constant flux density, the power required per kilogram to magnetize the iron core of a transformer is 0.8 W at 25 Hz and 2.04 W at 60 Hz. The power required per kilogram for 100 Hz is

3.4W Signup and view all the answers

Study Notes

Power Factor and Alternators

Power factor in alternators is influenced by rotor speed, core losses, load connected, and armature losses.

Fluorescent Lights

Flickering of fluorescent lights is usually caused by low frequency.

Frequency Theorems

Shannon Theorem is specifically utilized for determining frequency-related issues.

Project Management

Activities on a project network can be represented by arrows and nodes.
The first step in scope planning involves defining objectives and customer requirements.

Accreditation

The Accreditation Board for Engineering and Technology (ABET) accredits engineering education programs.

CRC Generators

A cyclic redundancy check (CRC) generator operates primarily on modulo 2 division.

Fast Track Definition

"Fast Track" refers to initiating construction before the completion of the design phase.

Electrical Components

Cascade amplifiers are designed to reduce load effects, typically resulting in high output impedance.
The output of a cascade amplifier is determined by the last stage.

Transformer Basics

The turns ratio in delta-wye transformers can be calculated as the ratio of phase voltages.

Incandescent Lamps

Operate most efficiently at unity power factor.

Software Maintenance

Key types of software maintenance include adaptive, corrective, and perfective maintenance, but customer-initiated maintenance is not recognized as a type.

Electrical Measurement

Important for electrical engineers to understand channel capacity based on signal-to-noise ratios and bandwidth.

Synchronous Motors

Can function in leading, unity, or lagging power factors. A synchronous motor without a mechanical load is termed as a synchronous condenser.

Voltage Regulation

Capacitive loads lead to negative voltage regulation in alternators.

Electrical Safety

Minimum earth wire gauge standards include options from 20 SWG to 8 SWG, with specifics depending on application.

Transformer Humming

Common cause of humming is vibrations in core lamination.

BJT Operation

BJTs operate as switches in saturation and amplify in the active region.

Pulses and RPM Calculation

Optical encoders count pulses to determine motor speed, and calculations are based on pulse count over time intervals.

Integration Testing

Integration testing checks the functionality of combined software modules through top-down or bottom-up approaches.

Harmonics

Common harmonic sources in electrical systems include variable impedance loads and power electronics.

General Concepts

Ethics in engineering refers to codes of behavior and general standards of right versus wrong, derived from philosophical and societal influences.### Transistor and Circuit Components
The collector region of a transistor is heavily doped.
In an OP-AMP based inverting amplifier, the input impedance is infinity and output impedance is zero.
In an OP-AMP based non-inverting amplifier, both input impedance is infinity and output impedance is also zero.

Communication and Signal Processing

A transmitter operating at 23.6 GHz with a power output of 20 nW has a receiver located 8 miles away.
According to the Nyquist Sampling Theorem, to prevent aliasing, the highest frequency in the signal must be less than half of the sampling frequency.
In optical communication, Frequency Division Multiplexing (FDM) is referred to as Wavelength Division Multiplexing (WDM).

Quality Management and Reliability

TQM stands for Total Quality Management—a holistic management approach.
Reliability of two circuit components is calculated using the formula: (R1 + R2) - R1R2.

Project Management and Engineering

The highest element in the Work Breakdown Structure (WBS) is the project itself, while the lowest is a work package.
Effective project management also involves scheduling tasks and estimating the required time and resources.

Power and Electromagnetism

Power doubling at a transmitter results in a 3 dB increase.
Power factor in an alternator relates to its load.
Slip frequency in a 50 Hz induction machine with a no-load speed of 2900 RPM can be calculated as 1.67 Hz.

Digital Systems and Computational Models

In HDL based digital systems, arithmetic multiplication can be challenging; solutions include sequential right shifts.
The most efficient ALU architecture for a Digital Signal Processor (DSP) designed for FFT operations with a 12-bit A/D converter is a fixed point multiplier with a 16-bit data path.

Logic and Analysis

Fan-out of a logic gate refers to the number of gates connected to its output.
Splitting a project into tasks and estimating resources is termed project scheduling.

Miscellaneous

Liquid metals include Hg (mercury), while Al (aluminum), In (indium), and Ni (nickel) remain solid at room temperature.
An early and late start calculation for activity highlights task management in projects.

Questions and Trivia

Multiple choice answers regarding electrical circuit analysis and characteristics need to highlight the correct attributes based on standard principles and engineering practices.

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Description

This quiz is designed for students preparing for the UPDA Electrical/Electronic Engineering examination. It covers important concepts such as power factors, fluorescent lights, and relevant theorems in electrical engineering. Test your knowledge and readiness for the exam with this review material.