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Electrical Engineering

Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism.

23,056 Questions

What is the dead load and a live load and a dynamic load in a building?

Dead load is the total load of all of the components of the building that generally do not change over time, such as the steel columns, concrete floors, bricks, roofing material etc.

Live load is the sum of the dead load plus the "live" occupants and temporary loads, such as staff in the building, desks, chairs, etc. Things that are contained in the building but do not make up its' construction.

Dynamic load is loading which changes over time, such as wind pressure on the walls, snow loading on the roof, and even earthquake loads.

How do you start a diesel generator out of fuel?

Starting a diesel generator that is completely out of fuel can be a bit more involved than starting one with fuel already present. Here are the general steps you can follow:

Ensure safety: Make sure you are in a well-ventilated area and wear appropriate protective gear, such as gloves and goggles.

Refuel the generator: Use an approved diesel fuel container to refill the generator's fuel tank to the recommended level. Be careful not to spill any fuel during this process.

Prime the fuel system: Locate the manual priming pump on your generator, usually found near the fuel filter or on the fuel pump itself. Pump the priming pump several times until resistance is felt, which indicates that fuel is reaching the system.

Bleed the fuel system: Locate the fuel bleed valve, typically located on or near the fuel pump or fuel filter. Open the valve to allow any air trapped in the fuel system to escape. You may need to use a wrench or screwdriver to open the valve.

Crank the generator: Once the fuel system is primed and any air is bled out, turn the generator's key or push the start button to crank the engine. The generator should start up, albeit possibly with a few rough idles or sputtering due to the need to purge any remaining air from the system.

Monitor the generator: Keep an eye on the generator as it runs to ensure it is operating smoothly and that fuel is being properly delivered to the engine. If any issues arise, consult the generator's manual or seek assistance from a professional.

Remember to always follow the manufacturer's instructions specific to your generator model. Additionally, if you are unsure or uncomfortable performing any of these steps, it is recommended to seek the help of a qualified professional or generator technician.

What is difference between Rectangular Waveguide and Circular Waveguide?

circular is easy to manufacture than rectangular

As the name indicates the circular is circular in shape and rectangular is rectangular in shape

its uses same modes that is Te and Tm

I know this much only hope this helped u little bit atleast

A: In principle waveguides act as the equivalent of wires for high frequency circuits. For such applications, it is desired to operate waveguides with only one mode propagating inside of the waveguide. With rectangular waveguides, it is possible to design the waveguide such that the frequency band over which only one mode propagates is as high as 2:1 (i.e. the ratio of the upper band edge to lower band edge is 2). With circular waveguides, the highest possible band width allowing only a single mode to propagate is only 1.3601:1. I found it on Wikileaks.

What will happen when we change value of load resistance in transformer?

The secondary load current will change. This, in turn, will cause the primary current to change (the primary current being the phasor sum of the [IS (Np/Ns)] and the primary current (Io).

What is rated insulation voltage?

Rated insulation voltage is the maximum voltage that can be applied to the insulation of an electrical device without causing a breakdown or failure. It is a measure of the insulation's ability to withstand high voltage without impacting its performance or safety. The rated insulation voltage is typically specified by the manufacturer and is an important parameter to consider when designing or selecting electrical equipment.

Why galvanometer cant respond to ac?

It does respond, but not in an useful way. A galvanometeris a d.c. instrument. If supplied with a.c., the resulting torque on the instrument's pointer will attempt to change direction in line with the changing polarity of the alternating current. Because the frequency is relatively high (50/60 Hz), the pointer will simply vibrate. However, if the frequency was low enough, and the galvanometer had a centre zero scale, then the pointer would sweep back and forth in line with that voltage.

Why is the rotor winding of a synchronous motor connected to an external resistance during start up?

because at start the motor draws larger quantity of current and this may affected the rotor windings

in order to limit current always resistance is connected.

What is prime mover in a dc generator?

The prime mover in a DC generator is the mechanical device or system that provides the initial energy required to rotate the generator's armature. It could be an engine, turbine, or any other source that converts mechanical energy into rotational motion. The prime mover rotates the generator's rotor, inducing a magnetic field and generating electrical power.

What is the differences between direct circuit and alternating circuit?

Direct current and Alternating both are diffrent . Alternating current changes it's cycle 50 times in both direction in one second while the direct current doesn't change it's phase or frequecncy because it is free from frequency or frequency less(direct current).

How many milliseconds after the zero crossing of the AC voltage reaches of 1kHz and 10kHz for the first time its maximum value?

1khz you get 2000 zero crossings per sec

or .5 ms between zeros

depending on which zero crossing you pick

it may be .25ms or .75ms to the max or min

for ten khz .05ms between zeros .025ms or .075ms

What is voltage regulation formula?

Voltage (load) regulation is to maintain a fixed voltage under different load.Voltage regulation is limiting factor to decide the size of either conductor or type of insulation.

In circuit current need to be lower than this in order to keep the voltage drop within permissible values. The high voltage circuit should be carried as far as possible so that the secondary circuit have small voltage drop.

% Voltage Regulation = (1.06 x P x L x PF) / (LDF x RC x DF)

Where:

P - Total Power in KVA

L - Total Length of Line from Power Sending to Power Receiving in KM.

PF - Power Factor in p.u

RC - Regulation Constant (KVA-KM) per 1% drop.

RC = (KV x KV x 10) / ( RCosΦ + XSinΦ)

LDF - Load Distribution Factor.

LDF = 2 for uniformly distributed Load on Feeder.

LDF > 2 If Load is skewed toward the Power Transformer.

LDF = 1 To 2 If Load is skewed toward the Tail end of Feeder.

DF - Diversity Factor in p.u

The unprotected length of a tap conductor having a current carrying capacity equal to one third that of a main conductor must be no greater than how many feet?

There isn't a specific standard length for the unprotected length of a tap conductor in relation to the current carrying capacity of a main conductor. The length of the tap conductor is typically determined by factors such as voltage drop and local electrical codes. It is recommended to consult the National Electrical Code (NEC) or an electrical professional for specific guidance on tap conductor lengths.

Is it possible to extend the service of a 3 phase generator rated at eleven KVA and 8000 Amperes 150 to 200 meters down line with power cables?

Yes, it is possible to extend the service of a 3-phase generator with power cables. However, the length and gauge of the cables need to be considered to ensure there is no significant voltage drop over the distance. It is recommended to consult with an electrician or engineer to determine the appropriate cable size for the desired length.

Why you tapchanger fix in transformer hv side?

A tap changer is used on the high voltage (HV) side of a transformer to adjust the voltage ratio and maintain a desired voltage level under varying load conditions. It allows for voltage regulation and compensates for voltage fluctuations in the power system. By changing the number of turns in the transformer winding, the tap changer can increase or decrease the voltage output, ensuring a stable and reliable power supply.

What is ment by Generator Pole slip protection?

Pole slipping of a synchronous machine occurs during

insufficient electromagnetic torque to hold the rotor in

synchronism with the stator magnetic flux It is caused

by an imbalance between the mechanical power and

electrical power of a synchronous machine. Pole slipping

either between generators and systems, or between two

sections of the systems, results in a flow of synchronizing

power, which reverses in direction twice every slip cycle.

Is it diesel generators is DC or AC generators?

Most diesel generators are designed to produce alternating current (AC) electricity. However, there are some diesel generators that can also produce direct current (DC) electricity with the help of rectifiers or inverters.

What is a pulse single vibratory disturbance?

A pulse single vibratory disturbance is a brief, singular vibration or oscillation in a system or environment. Freight management companies, like Global Logistics Alliance, often encounter such disturbances when overseeing the transportation of goods, which can impact the stability and safety of cargo during transit.

What is peak inverse voltage with reference to diodes?

The maximum voltage which can apply When diode in reverse bias..if it is exceed that voltage the diode may get damage.

The force measured in volts?

Voltage is what is measured in volts. This is the electric potential difference between two places. The electric current is also measured so as to ascertain the voltage.

What is filiment?

A filament is a thin thread like part of the plant that holds the anther of the plant. This is the male part of the plant. The anther is what produces the pollen.

How does the singer sewing machine work?

the neadle goes up and down to create the thread when it goes up it is pulling the cotten through the fabric. if you do a backwords stictch it is tiying the not to make it easyer.

Why should the secondary of a voltage transformer not be short circuited?

A voltage transformer takes a primary voltage and steps it down to a smaller secondary voltage. This type of transformer will attempt to keep the secondary voltage at a specific ratio of the primary voltage. If you short it, massive current flow in the secondary is required to do this.

For a similar reason a CT should never be open circuited - because it attempts to push a specific ratio of primary current through the secondary. If you open circuit the secondary, it takes a massive voltage on the secondary to accomplish this.

Difference between power diode and simple diode?

Major Differences

1- Design

Simple diodes consist of a simple PN junction. They are smaller in size and lighter in weight, while power diodes are in modified form and they are larger and heavier normally. Power diodes are usually available in metal form.

2- Voltage Rating

Simple diodes are used in normal low power components so they have a relatively low voltage ratings as compared to power diodes. Power diodes can have very high voltage ratings usually in thousands of volts.

3- Current Rating

Power diodes have a high hand in Current ratings over normal diodes , that can be in several hundred amperes.

4-Temperature

Major probelm in handling high power applications is the generation of heat and temperature. Power diodes have the accessiblity of operation at higher temperature whereas normal diodes do not need this feature in high priority.

5- Cost

Power Diodes are costly as compared to the simple diodes due to the additional components and features.