The root mean square of the alternating current is same as __ value

Two single-phase transformers are connected open-delta bank supplying a balance 3-phase load of 86.75 kVA. What is the KVA rating of each transformer?

In a power plant, a reserve generating capacity which is in operation but not in service is known as

Which of the following power plants needs highly skilled/qualified engineers for its operation

The purpose of a grid system is to

A charged capacitor and an inductor are connected in series. At time t = 0 the current is zero. But the capacitor is charged. If T is the period of the resulting oscillations, the next time after t = 0 that the charge on the capacitor is a maximum is:

When a power plant is not able to meet the demand at consumers. It will resort to?

The units of magnetization are:

The main reason that alternating current replaced direct current for general use is:

Repeated starting and stopping of a motor is referred to as

A rice mill will be served by two units of 50 kVA transformers, 7.620 kV/240 V. The transformers will be installed as open-delta bank to serve the three-phase load of the rice mill. What is the maximum kVA load that this bank can carry without overloading?

In a single-phase transformer, the core loss is 60 W at 40 Hz and 95 W at 60 Hz both measured at the same maximum value of flux density. Find the core losses in W at a frequency of 50 Hz.

A 6,000 volts generator supplies power to the transmission line with 3 loads A, B, and C. The loads are located at 4, 6, 10 km from the generator and draw currents of 75, 25, and 50 A, respectively. The resistance of the transmission line is 0.05 ohm per kilometer. What is the maximum percentage voltage drop from generator to load?

Which of the following type of fault that used only the equivalent positive impedance of the circuit in short-circuit calculations?

The electric motor generally used in household food mixers.

Which dc motor cannot be used without a load connected to it?

Base load plants are designed to supply power at

For constant transmission efficiency, voltage is increased n times. The size of the conductor would be:

A transformer has a reactance of 0.04 pu. If the secondary of the transformer is short circuited with nominal voltage applied to the primary, the symmetrical short circuit current will be

A balanced delta connected load has impedances Z1=Z2=Z3. What is the per phase equivalent impedance in wye?

Tall growing plants refer to plants, vines and other plant species which grow or have potential to grow more than ____ meters in height from the ground

KCL works on the principle of which of the following

The law that induces emf and current always opposes the cause producing them was discovered by

Out of the following given choices for polyphase transformer connections. Which one will you select for three to two phase conversion

A power station supplies 60 KW to a load over 2500 ft of a 000 2-conductor copper feeder the resistance of which is 0.078 per 1000 ft. The bus bar voltage is maintained constant at 600 Volts. Determine the maximum power which can be transmitted.

One primary and one secondary terminal of a two-winding transformer are connected to an ohm-meter instrument. What will be the reading on this instrument?

Which of the following cant attain the capacity of 100 MW

The location of the lightning arrester is

Which of the following is not a consideration in surge arrester?

The per-phase line loss in a 40 km long transmission line is not to exceed 60 kW while it is delivering 100 A per phase. If the resistivity of the conductor material is 1.72 x 10^-8 ohm-meter, determine the required conductor diameter

Two 110-V light bulbs, one “25W” and the other “100W” are connected in series to a 110 V source. Then, which of the following statement is correct with regard to above sentence

The resistance of resistor 1 is twice the resistance of resistor 2. The two are connected in series and a potential difference is maintained across the combination. Then:

A certain station in Luzon has 36kV, 3-phase, is to supply 12MW load at 30kV and 0.8 pf lagging over a 3-phase transmission line. Find the resistance of the line if the length of the transmission line is 4,000 meters and the efficiency is 90%.

The growth rate of the energy consumption in our country is 6.9%. In how many years will the energy be quadrupled?

When one coil magnetically coupled pair has a current of 5A, the resulting flux is Φ11 = 0.2 mWb and Φ12 = 0.4 mWb respectively. If the turns are N1 = 500 and N2 = 1500, Find L2.

What is the minimum distance receptacle outlet of a show window in meters?

What is the nominal supply voltage specified by the Philippine Electrical Code for residential homes?

A light source measuring 25 candela is compared with a lamp of unknown intensity using a grease-spot photometer. The two light sources are placed 1 meter apart, and the grease spot is moved toward the standard light. When the grease sport is 25cm from the standard light source, the illumination is equal on both sides Compute the unknown intensity.

A circular top is located 4m below and 3m to the left of a lamp that emits 2000 lumens. What illumination is provided on the surface of the table?

Republic Act No. 7920, the New Electrical Engineering Law, was approved on ______.

The government agency created under Presidential Decree 269, whose additional mandates include preparing electric cooperatives in operating and competing under a deregulated electricity market

This ANSI Device number refers to AC Inverse Time Overcurrent Relay

This ANSI Device number refers to Differential Protective Relay

Two alternators operating in parallel supply of 2500 KW to a load at a power factor of 80% lagging. If one machine delivers 1200 KW at a power factor of 95% lagging. What is the power supplied by the other machine?

A motor shall be marked with following information: Manufacturer’s name, Rated Volts, Full load current, Rated Frequency, and Number of phases. This is a/an _____ rule in the Philippine Electrical Code.

When a generator is being driven at 1200 revolutions per minute. The generated EMF is 230 Volts. What is the generated EMF if the speed is reduced to 1100 rpm, the field flux remains unchanged.

Water flows from a reservoir with an elevation of 25 m out a short pipe that contains a turbine power. The exit is at an elevation of 5 m. If the flow rate is 0.01 m3 /s, the maximum power output is.

A hydroelectric power station is supplied from a reservoir having an area of 50 km2 and a head of 50 m. If overall efficiency of the plant is 60%, find the rate at which the water level will fall when the station is generating 30000 kW.

A single phase transformer rated 100kVA, 2.4kV/240V. If 240V winding is short-circuited, the rated current flows when the voltage applied is 2.4kV winding is 1.054kV. The power input is 3.89kW. What is the value of the reactance referred to high-voltage winding?

A 120V, 200A single phase is supplied by a source 1000 ft. away through a copper conductor with a diameter of 0.45in. and resistivity of 10.4 Ω-CM/ft. What voltage must the supply be?

In two-wattmeter method, the reading of one of the wattmeter’s will be zero when

For an unbalanced load, which connection is suitable?

In a 3-loop network, we get the following equations by Kirchhoff’s law: 159 I1 – 50.9 I2 = 1, 470 I1 – 2400 I2 + 370 I3 = 1, 142 I1 – 380 I3 = 1. Where I1, I2 and I3 are loop currents. If I3=2.53mA what is the value of the current of I1 in mA?

Which is not a characteristic of an ideal transformer?

Which of the following has the greatest effect in decreasing the oscillation frequency of an LC circuit?

A capacitor is an LC oscillator has a maximum potential difference of 15 V and a maximum energy of 360μJ. At a certain instant the energy in the capacitor is 40μJ. At that instant what is the emf induced in the inductor?

Determine the GMR of a three-equal strands conductor in vertical formation in terms of r of an individual strand?

A capacitor is an LC oscillator has a maximum potential difference of 15 V and a maximum energy of 360μJ. At a certain instant the energy in the capacitor is 40μJ. At that instant what is the emf induced in the inductor?

An ice plant has 100 kW, 80% lagging, requires an open delta bank. What is the transformer rating of the system to be implemented?

Which of the following instrument is used to measure high resistance as in the measurement of insulation resistance?

Which of the following transformer has only one winding?

The area of dam reservoir is 218 x 212 ft, if the dam lost 1 ft of its depth produced an output of 100 hp at 70% eff. What is the original height of the reservoir?

In a purely capacitive circuit the current

A current is clockwise around the outside edge of this page and a uniform magnetic field is directed parallel to the page, from left to right. If the magnetic force is the only force acting on the page, the page will turn so the right edge.

Given a transformer of 8 MVA, 69 kV/13.8 kV with 7% impedance, find the unit impedance at 100 MVA, 67 kV base.

Which one does not belong to the technical performance standards of Philippine Distribution Code?

A continuous load is defined as a load that is expected to draw its maximum current for __________ .

For hermetic motor, what rule is the disconnecting means is 115% of the full load current?

When a 20-ampere, 125-volt receptacle outlet is installed, in which of the following listed locations is the receptacle required to have GFCI protection?

What is/are the main reason/s for using high voltage in transmission of power in the grid system?

In which type of electronic communication does the information travel in two directions?

The winding of power transformer usually develops short circuit on account of

A device that can carry and interrupt load current even in case of a fault by used of separate contacts.

Copper loss of a transformer is determined by means of a/an _______ test

Which of the following is core losses are negligible during a short-circuit test conducted on transformer?

Diesel power plant is best suited as

Refers to burning of waste and other materials, excavation, quarrying, construction, and other activities of the same nature and character, which are performed partially or wholly inside the power line corridor which threaten or endanger the continuous and uninterrupted conveyance of electricity;

How much reactive power must be supplied by parallel capacitors to a 1000 kW load with a 0.6 lagging power factor to increase the overall power factor to 0.85 lagging?

What is the equivalent capacitance of a two-series capacitor?

An inductive load, consisting of R and X in parallel, feeding from a 2.4 kV rms supply, absorbs 288 kW at lagging power factor of 0.80. What is the value of X in ohms?

An impedance, 2.2+3.81j ohms, is connected across a 220V source. If a pure resistor is connected in parallel with the original impedance, what should be the ohmic value, if the power delivered to the circuit is 16.6W, overall unity power factor.

A certain ammeter has an internal resistance of 1 ohm and a range from 0 to 50 mA. To make its range from 0 to 5A.

Four 20-Ω resistors are connected in parallel and the combination is connected to a 20-V emf device. The current in the device is:

A 245-kV transmission line has a series impedance of (4 + j60) Q and a shunt admittance of j2 x 10^-3 S. Using 100 MVA and the line voltage as base values, calculate the per-unit impedance and per-unit admittance of the line.

What is earthing or grounding?

The following are types of AC motor starters except:

Single-Side Band signal produces a peak-to-peak voltage of 720 V on voice peaks across a 75-ohm antenna. What is the peak envelope power?

Which of the following is a conductor of electricity?

In a parallel circuit the potential difference across the resistance

In DC machines, lap winding is used for

A 69-kV, three-phase short transmission line is 16 km long. The line has a per-phase series impedance of 0.125 + j0.4375 Ω per km. Determine the sending end voltage, voltage regulation, the sending end power, and the transmission efficiency when the line delivers 70 MVA at a 0.8 lagging power factor at 64 kV.