Compilation of Past Board Examination Questions Electrical Engineering

ESAS

This is the number system used in fault calculations to limit the values of numbers to minimum.

per unit

When the DBV of insulating oil is lower than the acceptable minimum, this is used to clear the oil of moisture and other impurities.

filter press

To ensure safety during maintenance of electrical system, this is provided on the main switch and padlocked.

danger tag

This is considered safety reminders to electrical practitioners.

safety meetings

On working overhead, like on poles or any structure 6 feet or higher above ground, this device/gadget is mandatory.

safety belt

When three-phase squirrel cage induction motor fails to start, one of the following is not one of the possible causes.

loss contact on the brush

When three phase induction motor runs hot among the causes are, except:

under load

When a DC motor fails to start, among the possible causes are, except:

broken ring

When a magnetic contactor produces buzzing noise, the possible causes are except:

failing insulation

In tightening electrical bolts, this quantity must be given highest consideration to prevent loss connection.

torque

When the rotor of a motor vibrates as it rotates, one possible cause is:

unbalanced rotor

These are installed on industrial ovens used for drying electrical machines, to ascertain uniform heat distribution.

aerators

When electrical machines and equipment’s are operated 10OC higher than their normal operating temperatures at regular frequency, its consequence is:

reduce its life span

The eddy current losses on electrical machines can be reduced by:

make the laminae thinner

During application of insulating varnish, to make sure of positive impregnation on the windings considered, it should be:

hot

When a lead – lead acid battery is fully discharged, its electrolyte turns into:

H2O

This kind of electric transformer is used to alter the phase angle or position of either voltage or current.

phase shifting

This is a part of the power system where change is to take place as per load requirement.

substation

The shunt fault on transmission lines that very seldom occur is the:

LLL

This transformer is designed to neutralize the unbalanced current on the Edison system.

zig – zag

This device/instrument is used to determine the correct pressure on the contacts of molded case circuit breakers.

spring balance

Ten to forty horsepower motors with service category of “easy”, and are to operate only one hour per day, is recommended for greasing every:

seven years

Motors with standard type of service like that of machine tools, fans, pumps and textile machines with rating of not more than 40 Hp., are to be regreased every:

five years

Vibration – displacement indicators are tools used for:

alignment

This electrical drawing is used to determine the flow of power from source to the load:

single line

The electrical standards used in the Philippines and as basis of the Philippine Electrical Code is:

NEMA – ANSI

As far as the New Electrical Engineering law (R.A. 7920) is concerned, this is a requirement before an electrical engineer’s license can be renewed by PRC.

CPE

Underwriters laboratory is an institution established by these groups, to evaluate manufactured electrical components and devices for safety:

Insurance companies

This is a laboratory instrument/tester used to measure DC and Ac voltages, current and even frequency.

Oscilloscope

A six leads delta induction motor is to be connected to an autotransformer starter, the leads to be connected together are:

1-6, 2-4, 3-5

A nine leads delta connected motor is to be connected to a primary resistor starter for its lower voltage rating operation, the leads to be joined together are:

1-7-6, 2-4-8, 3-5-9

This is an electronic gadget which can be used in lieu of magnetic contactor.

SCR

When connecting electrical transformers in parallel, among the requirements to be satisfied are as follows, except:

same exciting current

When connecting DC generators in parallel, among the requirements to be satisfied are, except:

same type

The horsepower rating of electric motor which is allowed by PEC to use its plug as its controller.

1/8 Hp and below

This is the type of ammeter used in an electrical circuit without causing opening in the circuit for its insertion.

Aota

This type of controller has pre-settings done on computers, and to actuate only if these settings have been satisfied while the controlled machine is in operation.

programmed logic

The part of the computer system that actually draws the electrical drawings to be used for construction.

plotter

In illumination, this is one factor that will determine the number of luminaires or fixtures to be installed in a given work area.

type of work

This type of switch is used to control a luminaire at two different locations.

three way

This is a method in illumination design where computer is a necessary tool.

point by point

In urban rail system, preference is given to DC over AC electric trains due to the former’s:

high torque

The combination of the multiple and series windings of a dynamo in their simplest form:

frog – leg

Of all magnetic materials known to man, this type exhibits the weakest intensity and torque.

diamagnetic

This mechanism is provided to most power breakers so that even if the closing coil is energized, it can still be tripped off.

trip – free

This is the minimum size of conductor for service entrance as per Philippine Electrical Code.

14 mm2

This is the minimum size of cable to be used as service entrance conductor as per Philippine Electrical Code.

8 mm2

Switching equipment can be installed in different ways as practiced by electrical practitioners except:

recessed

In electro magnets, the true main source of magnetomotive force is the:

amp-turns

This is the type of power plants that has destroyed the ecological balance in wide spectrum.

hydro

This is the type of power plant that is responsible for the depletion of air in large volumes.

dendro

This is the type of power plant that utilizes the stored energy on the building particles of matter.

nuclear

This is the process of harnessing the store energy of atoms.

fission

This is believed to be the fuel of the future when hydro carbons will be fully depleted.

deuterium

In magnetic circuits, this is the reciprocal of permeance.

reluctance

The average produced by the ignition coil of most modern automobiles:

20 – 25 kV

When two coils share a common magnetic flux, the proportionate percentage that reaches the passive coil is called:

coefficient of coupling

The forces between electrically charged bodies has been defined by:

Coulomb

The process of strengthening the diminished residual magnetism of generator poles is known as:

flashing

Compound generators cane be classified according to the following manner, except:

winding

The type of DC generator wherein the internal and external characteristics are somewhat the same:

series

This is a solenoid formed in circular appearance.

torroid

This is the magnetic induction on the center of an atom caused by the orbiting amperean currents.

magnetic torque

Hyperconductors as used in scientific endeavors is associated with:

cryogenic bodies

The opposite of dielectric is:

conductivity

These are the materials placed on nuclear reactors to produce the heat needed to create steam for power generation.

radioactive

Type of lamps used to show the electrical position or mode of a certain electrical device or equipment that is not readily within the view of the operator.

indicating

When an energized magnetic contactor chatters, one possible cause is:

excessive spring tension

The light emanating from an operating fluorescent lamp is caused by the collision of the electrons thermionically emitted from its heaters and the molecules of this gas.

phosphorus

The danger of the step down autotransformer as power source if the common winding accidentally opens is:

load will be burnt

The main difference between RSC and the GI pipe for water lines is their construction’s:

smoothness

The danger of AC voltage when used on submarine electrical transmission or even on distribution is:

it destroys aqua marine life

The disadvantage of high speed electrical machine as compared to the one with moderate speeds;

prone to excessive wear

To make sizes of electrical machines smaller yet maintaining its original capacity, this action can be done;

increase frequency

When the maximum demand of two branch circuits occur at the same time, their diversity factor is;

none of the above

In parallel operation of alternators, the voltage of incoming machine must be;

slightly higher

Before the incoming alternator synchronizes with the running machine, its frequency compared to the bus must be;

1/10th higher

When the lamps used for synchronizing are both bright and dark at the same time, they are said to be in;

unison

This equipment is used to determine the actual torque and brake horsepower of electric motors and related machines.

dynamometer

In a Power Plant, this is where the lighting and power supply for its own facilities comes from.

station service

When the capacitor installed on a capacitor motor is shorted, the motor;

stalls

In a given City, this offer is the person responsible for the same installation of electrical wiring for every structure.

None of the above

High Voltage system can be classified further into, except;

mega high

Power circuit breakers are also classified according to operation. Some of these are, except;

inclined break

A 3 phase motor with 12 leads can be controlled by;

all of the above

This kind of thermal power plant uses no fuel to produce super heat steam.

geothermal

For electric motors with NEMA design code, the one with low starting torque is;

NEMA F

A wye connected 25 Hp induction motor rated 480/240 volts has nine leads. IF this is to be operated at its higher voltage rating, the following leads must be joined together.

4-7, 5-8, 6-9

To approximate the capacitance in microfarad of capacitor to be used for capacitor start motor, use the formula:

2650 x amps/volts

The average power factor of fluorescent and mercury lamps:

50 – 95%

In computing for the horsepower rating of motor to be used for the main compressor of an air-conditioning unit from 1/2 to 5 tons, the rule of thumb is:

1.25 Hp/ton

In measuring the depth of the sea in relation to the installation of submarine cables, the unit of length commonly used is the:

fathom

This is an electrical measuring instrument used to measure the work done in joules per second.

wattmeter

SCADA as applied to power plant operation stands for:

supervisory control and data acquisition

When the magnetic fluxes due to the series and shunt field windings are aiding, the machine is said to be:

cumulative

This is used to weaken the flux due to the series field winding of a DC generator.

diverter

This is used to predetermine the electrical energy as well as the demand that a power plant will supply to its prospective load.

projected load graph

This instrument is used to find the area covered by the load graph with respect to the horizontal axis.

planimeter

On the control room of Central Power Station, this is used to call the attention of operators when something is wrong with the system.

annunciator

For electrical machines that will be stored for sometime, to avoid corrosion, one of the following must be observed:

make its temperature constantly warm