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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
How do you calculate volt drop with length and resistance?
cable length multiply with the design current and multiply again by mV/A/m (check on site guide) then devide it by 1000. then u will get the volt drops. BY; MAMERGA
Why The Excitation current is non-sinusoidal when applied voltage is sinusoidal?
excitation voltage is sinusoidal because it is taken from the terminal of alternator but excitation current is non-sinusoidal because it always dc.
4 megawatts - heaps
The megawatt is equal to one million watts. Many events or machines produce or sustain the conversion of energy on this scale. For example: lightning strikes, large electric motors, naval craft (such as aircraft carriers and submarines), engineering hardware, and some scientific research equipment, such as supercolliders and large lasers. A large residential or commercial building may consume several megawatts in electric power and heat.
How does the number of wraps of wire affect the strength of an electromagnet?
The more turns of wire in an electromagnet the stronger the magnetic field.
Impedance is a vector sum using the formula Z = square root (XL2 + R2); where Z = impedance, XL = inductive reactance, and R = resistance. Therefor the formula for a circuit where XL = 64ohm's and R = 36ohm's is Z = square root(642 + 322); Z = 71.6ohms.
What is a purely capacitive circuit means?
A 'purely capacitive' circuit is a theoretical, or 'ideal', circuit, in which the resistance and inductance of the circuit is ignored, and in which the load current theoretically leads the supply voltage by exactly 90 electrical degrees. It is often used as a means of introducing students to the behaviour of 'real' a.c. circuit which contain contain resistance and inductance, as well as capacitance.
What are the characteristics of dc shunt generator?
The open-circuit characheristics and the load characheristics
How is Ampere-hour calculated if four 65 Ah batteries in series for UPS?
The ampere-hour rating of series connected batteries is the same as that for one battery, so the ampere-hour rating of four 65 Ah batteries in series is still 65 Ah.
The reason for this is Kirchoff's current law - the signed sum of the currents entering a node is zero - or - the current at every point in a series circuit is the same.
What is difference between cleat and conduit wiring?
Cleat wiring is exposed while in conduit wiring the wires are well protected inside tubes/pipes.
Applications of maximum power transfer theorem?
Increasing the power delivered to load motor in an electric vehicle design and a solar array loaded by a grid tied inverter are some applications of maximum power transfer theorem. Maximizing the power delivered to transmission line or antenna in a radio transmitter final amplifier stage design is another practical application.
Formula for calculating btu for a room metric?
Calculating your air conditioning requirements
Heat Load
The amount of heat generated is known as the heat gain or heat load. Heat is measured in either British Thermal Units (BTU) or Kilowatts (KW). 1KW is equivalent to 3412BTUs.
The heat load depends on a number of factors, by taking into account those that apply in your circumstances and adding them together a reasonably accurate measure of the total heat can be calculated.
Factors include:
- The floor area of the room
- The size and position of windows, and whether they have blinds or shades
- The number of room occupants (if any)
- The heat generated by equipment
- The heat generated by lighting
Floor Area of Room
The amount of cooling required depends on the area of the room. To calculate the area in square metres:
Room Area BTU = Length (m) x Width (m) x 337
Window Size and Position
If, your room has no windows, you can ignore this part of the calculation. If, however there are windows you need to take the size and orientation into account.
South Window BTU = South Facing window Length (m) x Width (m) x 870
North Window BTU = North Facing windows Length (m) x Width (m) x 165
If there are no blinds on the windows multiply the result(s) by 1.5.
Add together all the BTUs for the windows.
Windows BTU = South Window(s) BTU + North Window(s) BTU
Occupants
You will have to take that into account people who normally working in the space. The heat output is around 400 BTU per person.
Total Occupant BTU = Number of occupants x 400
Equipment
Clearly most heat in a room is generated by the equipment. This is trickier to calculate that you might think. The wattage on equipment is the maximum power consumption rating, the actual power consumed may be less. However it is probably safer to overestimate the wattage than underestimate it.
Equipment BTU = Total wattage for all equipment x 3.5
Lighting
Take the total wattage of the lighting and multiply by 4.25.
Lighting BTU = Total wattage for all lighting x 4.25
Total Cooling Required
Add all the BTUs together.
Total Heat Load = Room Area BTU + Windows BTU + Total Occupant BTU + Equipment BTU + Lighting BTU
This is the amount of cooling required so you need one or more air conditioning units to handle that amount of heat.
How do you know the primary or secondary side of a transformer?
The primary side is usually labelled 'H', the secondary is often labelled 'L'.
Primary wiring will often be smaller, since the current carrying capacity doesn't have to be as high on the primary side.
The best thing to do would be to check with the manufacturer. They should have documentation stating what is primary and secondary.
CommentThe above answer only applies to step-down transformers. The simple answer is that the primary winding is the winding connected to the supply, whereas the secondarywinding is the winding connected to the load. These terms have nothing to do with voltage levels.
When will current power outage be fixed?
This is best answered by your local utility. They should have a customer phone number for you to call.
Power outage repair time can be anywhere from minutes to weeks, depending on the cause, and extent of damage to the system.
How do you hold your load longer?
There are lots of ways to hold your load longer during sex. Try:
Changing positions to having her on top. It's a lot less stimulating to the guy.
Focus on breathing deeply, and not going too fast...that's when you pop.
Pay attention to what she really likes and keep doing it....the idea is to have good sex, not sex that lasts forever. If both people orgasm it's a win!
What were advantages and disadvantages of wheatstone bridge?
disandvantage:-the wheatstone bridge is not applicable for high resistances
advantage:-1)it shows a null measurement(i.e.-potential difference across the end points of the bridge is zero)
2)since it is an arrangement of 4 resistors ...it is useful to find one of them in terms of other 3
Input resistance and output resistance of Voltage series feedback amplifier?
output resistance decreases and input resistance increases
What are the effects of power on a resistive device?
Current passing through a resistor, et al, causes heat. The heat causes the resistance of said resistor to decrease, which causes current to increase, and the cycle just keeps going until the circuit burns out.
What is the equivalent Hz to mA?
Hz is a unit of frequency. mA is a sub-unit of current. The two are not related.
Why is an automatic toaster open loop system?
since i doesnt take any feedback and the bread pops out as soon as the time is over. whether the bread was toasted or not is not seen, hence it is open loop.
Primary current is a flow to be measured that cannot be safely passed through the measuring device. A current transformer is used to provide a lower level, secondary current that can be passed safely through the measuring device. Primary current is measured as a secondary current, multiplied by the turns ratio in the current transformer.
