A 15 hp, 230-V, 1800 rpm shunt motor has an efficiency of 90% at full load. The resistance of the field is 440 ohms. What is the full-load armature current?

A 15 hp, 1200 rpm, 230 volts dc shunt motor has an armature and field resistances of 0.25 and 100 ohms respectively. The full-load efficiency is85%. What would be the starting resistance if the armature current will be limited to 200 A at full-load load value? (Troubleshoot: 200%)

The primary disadvantage of FM in AM is

As a loop of wire with a resistance of 10 Ω moves in a constant non-uniform magnetic field, it loses kinetic energy at a uniform rate of 4.0 mJ/s. The induced current in the loop:

The boundary of the protection system is determined by the location of

The illumination of a surface 3.40 m directly below a light source is 25 lux. Find the intensity of the light source.

A certain voltmeter has an internal resistance of 10k-o and a range from 0 to 100 V. To give it a range from 0 to 1000 V, one should connect:

Zero-sequence current will flow in a transmission line when there is

A uniform magnetic field makes an angle of 30◦ with the z axis. If the magnetic flux through a 1-m2 portion of the xy plane is 5 Wb then the magnetic flux through a 2-m2 of the same plane is __ Wb.

The changes in volume of transformer cooling oil due to variation of atmospheric temperature delay during day and night is taken care by which part of the transformer?

Which of the following will you connect to make a galvanometer into an ammeter?

Which of the following will you connect to make a galvanometer into an voltmeter?

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:

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 inductor is a maximum is:

Three 100 KVA single phase transformers are connected in closed delta to supply a three-phase load and the total output power is 300 KVA. If one of these transformers is to be removed and the transformer bank is operated as an open-delta connection, what will be the new output of this new connection in kVA?

Three single-phase transformers rated 25 kVA each are connected in delta-delta to supply a balanced load of 75 kVA. One transformer is removed for repair, what is the kVA of each remaining transformer?

A 69 kV, three-phase short transmission line is 16 km long. The line has a per phase series impedance of. (missing given) Determine the transmission efficiency when the line delivers 70 MVA, 0.80 lagging power factor at 64 kV.

Troubleshoot: impedance of 0.125 + j0.4375

A transmission line cable consists of 26 strands of identical copper conductor, each 1.255 mm in diameter. The length of the cable is 10 km but, because of the twist of the strands, the actual length of each conductor is increased by 5%. If the resistivity of the copper is 1.72 x 10-8 ohm-meter, what is the resistance of the cable?

A 30-mile, three-phase transmission line is to deliver 20, 000 kW at 69 kV at 85% power factor. The line resistance is 0.324 ohm per mile and inductive reactance is 0.737 ohm per mile. What is the line loss?

A generator delivers a load through a pair of wires, each of which has a resistance of 0.06 ohm. If the load voltage and power are 120 v and 4.8 kW, respectively, what is the generated voltage?

The conductors of a three-phase transmission line are arranged in the form of an equilateral triangle with sides 6 m each. If the conductors are 500 mils in diameter, and the line is 25 km long, what is the inductance per phase?

At time t= 0 the charge on the 50-μF capacitor in an LC circuit is 15μC and there is no current. If the inductance is 20 mH the maximum current is:

Which of the following protects a cable against mechanical injury during handling and laying?

I. Armouring

II. Bedding

Two resistors are connected in parallel across a potential difference. The resistance of resistor A is twice that of resistor B. If the current carried by resistor A is I, then what is the current carried by B?

Which of the following motors is generally used in toys ?

Power lost due to alternating magnetization and demagnetization of the core material

The purpose of providing dummy coils in the generator is

Two 110-V light bulbs, one “25” 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 current flowing in the armature of a dc motor is

The current is zero in a conductor when NO potential difference is applied because

The voltage regulation is MORE consider in the design of

The voltage applied across an electric press was reduced by 50%. The power consumed by the press will be reduced to

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

___________ diode exhibits variable capacitance that depends on the reverse voltage.

Tesla is the unit of

The unit of magnetic dipole moment is

Which of the following protective device operates on the principle of Kirchhoff’s Current Law?

The magnetic torque exerted on a flat current-carrying loop of wire by a uniform magnetic field B is

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

A certain ammeter has an internal resistance of 1Ωand a range from 0 to 50 mA. To make its range from 0 to 5 A, use:

A 4,400 v, 60 Hz transformer has core loss of 840 watts, of which one-third is eddy current loss. What is the core loss when the transformer is connected to a 4,600 v, 60 Hz source?

A piece of conductor 10 cm long moves across a magnetic field of 10k gauss at a velocity of 120 cm/sec. What is the voltage across the conductor?

Which of the following statement is false?

Which of the following is a variable renewable source of energy (VRE)?

Which of the following relays are used for phase fault on long line?

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

Which of the following type of fault used the equivalent positive and negative sequence impedance of the circuit in the short-circuit calculation?

An unconventional conductor consists of three strands arranged vertically. Find the GMR in terms of radius r of and individual strand.

At what distance from a wall will 40 Cd lamp provide the same illumination as 80 Cd lamp located 4 m from the wall?

Copper loss of a transformer are determined by means of a/an ____ test.

An ammeter consists of a meter movement in parallel with a _________.

A voltmeter consists of a meter movement in series with _________.

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:

If R is the distance from a magnetic dipole, then the magnetic field it produces is proportional to: 

The magnetic field outside a long straight current-carrying wire depends on the distance R from the wire axis according to

Nine identical wires, each of diameter d, and length L, are connected in parallel. The combination has the same resistance a single similar wire of length L but whose diameter is

Nine identical wires, each of diameter d, and length L, are connected in series. The combination has the same resistance a single similar wire of length L but whose diameter is

An ACSR conductor has (n – 1) layers around its single center strand, the total number of strands will be

A 120-V power line is protected by a 15-A fuse. What is the maximum number of “120 V, 500W” light bulbs that can be operated at full brightness from this line?

Two equal charges of opposite signs are separated by a horizontal distance of 70 mm. If the resultant electric field at the midpoint of the line is 4 x 104 N/C. What is the magnitude of each charge?

What contains in each cell site of  cellular telephone system?

The trip coil of a circuit breaker is connected through a CT of ratio 50:1. If the normal line current is 160 A and circuit breaker is to operate at 125% normal, the trip mechanism should be set to operate at trip current of ___ A.

A 3-phase motor is rated for 50A. What is the minimum inverse time delay circuit breaker rating?

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

It is defined as the total number of sustained Customer power Interruptions within a given period divided by the total number of Customers served within the same period.

Which is not a standard distribution voltage in the Philippines?

A 50 cm long conductor is moved in a field of density 1 Wb/m^2 at a velocity of 30 m/s. What is the emf induced if the motion is perpendicular to the field?

The area of one plate of a two-plate glass capacitor is 0.07 m^2 and the capacitance is 0.01 μF. If the dielectric constant of glass is 7.5, what is the separation between plates?

A permeable substance is one

R-rate fuses are designed to interrupt

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?

For two alternators operating in parallel, if the load shared by one of them is to be increased, its field excitation is

Four wires meet at a junction. The first carries 4A into the junction, the second carries 5A out of the junction, and the third carries 2A out of the junction. The fourth carries:

Faraday’s law states that an induced emf is proportional to: 

Four 20-Ω resistors are connected in series and the combination is connected to a 20-V emf device. The potential difference across any one of the resistors is: 

The Pentium is      bit microprocessor that was introduced by Intel on March 22, 1993 as the very first CPU in the Pentium brand.

A system operates at 220 kVA and 11 kV. Using these quantities as base values, what is the base impedance of the system?

What is the device function number is instantaneous overcurrent relay.

If the fore finger points in the direct on of the magnetic field, the thumb points in the direction of motion of the conductor, then the middle finger will point in the direction of induced emf (or current)". This is known as:

The per-phase constants of a 345-kV, three-phase,150-km-long transmission line are resistance = 0.1ohm/km, inductance = 1.1mH/km, and capacitance = 0.02 uF/km. The line supplies a 180-MW load at 0.9 power factor lagging. Using the nominal-pi circuit, determine the sending-end voltage. (Looksfam)

Given: la = 656; lb= -17 - j17.31 ; lc = 17 + j31. Find the positive sequence la1?

A wind generator with an efficiency of 80% has blade diameter of 20 m. If the wind velocity is 35 km/h, how much power in kW is obtained from the generator?

The Primary of a 3:1 step-up transformer is connected to a source and the secondary is connected to a resistor R. The power dissipated by R in this situation is P. if R is connected directly to the source it will dissipate at a power of:

The breakdown voltage of the dielectric of a cable is 800 volts/mil. A factor of safety of 4 is used. Find the maximum voltage at 3.5 mils. 

In an antique automobile, a 6-V battery supplies a total of 48W to two identical headlights in parallel. The resistance (in ohms) of each bulb is:

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?

The current is zero in a conductor when NO potential difference is applied because

A single phase, 20 km line has a total inductance of 35 mH. The distance between the two conductors is 59 inches. Find the GMR of the conductor.

When the service consists of a multiple of individual disconnecting means for grounded system, the main bonding jumper is required to be located in ____ disconnecting mean/s.

A 3-H inductor has 2000 turns. How many turns must be added to increase the inductance to 5 H?

Only one of the two devices on a link can transmit; the other can only receive.

What is the actual voltage of the high-leg (middle) for the three-phase, four-wire delta grounded system 240/120 V secondary voltage?

Silica gel prevents air moisture from entering the outdoor transformer tank. It is placed in the 

When a generator is being driven at 1200 rpm, the generated emf is 230 V. What is the generated emf if the speed is reduced to 1100 rpm, the field flux remains unchanged.

A 600 V, 30,000-ohm voltmeter is used to measure the insulation resistance of a motor. When connected in series with the insulation across a 240-volt line, the Instrument reads 5 volts. What is the value of the insulation resistance of the motor?

A 100-kVA, 60-Hz, 2200-V/220-V transformer is designed to operate at a maximum flux density of 1 T and an induced voltage of 15 volts per turn. Determine the number of turns of the primary winding

What is the maximum power that can be transmitted over a three-phase  short transmission line having a per-phase impedance of (0.3 + j0.4) ohm, if the receiving-end voltage is 6351 volts per phase and the voltage regulation is not to exceed 5 percent?

The per-phase constants of a 345-kV, three-phase, 150-km-long transmission line are resistance = 0. 1 Ω/km, inductance = 1.1mH/km, and capacitance = 0.02 uF/km. The line supplies a 180-MW load at 0.9 power factor lagging. Using the nominal-II circuit, determine the sending-end voltage.

A three-phase, wye-connected, 20-MW load of power power factor 0.866 lagging is to be supplied by a transmission line at 138 kV. It is desired that the losses not exceed 5 percent of the load.  If the per-phase resistance of the line is 0.7 Ω, what is the maximum length of the line?

A 138-kV, three-phase short transmission line has a per-phase impedance of (2 + j4) Ω. If the line supplies a 25-MW load at 0.8 power factor lagging, calculate the efficiency of transmission.