Electrical Engineering

If you stretch a wire, it would become longer, and therefore thinner. The cross sectional area will decrease and so the resistance will increase.

in the real world, if it's stranded wire, the strands will likely break. Solid wire would not stretch evenly, and in either case insulation will tear, so I wouldn't recommend stretching a wire.

A basic capacitor is made up of two conductors separated by an insulator, or dielectric. The dielectric can be made of paper, plastic, mica, ceramic, glass, a vacuum or nearly any other nonconductive material. Some capacitors are called electrolytics, meaning that their dielectric is made up of a thin layer of oxide formed on a aluminum or tantalum foil conductor.

Yes, you can use three single phase transformers on three phase applications and interconnect them to serve as a single transformer or you could use one single phase transformer fed from two of the three lines in a step down application.

The simplest way to start a three-phase induction motor is to connect its terminals to the line. In an induction motor, the magnitude of the induced EMF in the rotor circuit is proportional to the stator field and the slip speed (the difference between synchronous and rotor speeds) of the motor, and the rotor current depends on this EMF. When the motor is started, the slip speed is equal to the synchronous speed, as the rotor speed is zero (slip equal to 1), so the induced EMF in the rotor is large. As a result, a very high current flows through the rotor. This is similar to a transformer with the secondary coil short circuited, which causes the primary coil to draw a high current from the mains. When an induction motor starts DOL, a very high current is drawn by the stator, on the order of 5 to 9 times the full load current. This high current can, in some motors, damage the windings; in addition, because it causes heavy line voltage drop, other appliances connected to the same line may be affected by the voltage fluctuation. To avoid such effects, several other strategies are employed for starting motors.

Depending on the size of the transformer, it can be protected by fuses, thermal elements, or by a full relay protection package, which could include overcurrent relays, differential relays, and distance relays.

The On/OFF action in UJT is controlled by emitter current

A transformer is a passive device while an amplifier is an active device. a transformer can amplify voltage but never power WHILE AN AMPLIFIER CAN amplify power's can you use it sure withing the limitation of the transformer and only to amplify volts.

Electrical Energy

A double pole switch can be used in either a 240V application where you'll need to disconnect 2 "hot" lines, or it is useful when switching a light from 3 different switches.

Disadvantage?

I suppose it could be a little confusing to face all those contacts on a double pole switch.

Digital transformation of the sampling rate of signals, or signal processing with different sampling rates in the system.

They both do. Voltage is a measure of electrical pressure. Amperage is a measure of electrical flow (current) (amount of electricity flowing). High voltage by itself will not kill you but will leave a nasty taste in your mouth. At the right pressure your heart can be stopped though by a single amp.

Is 120 V the primary or secondary voltage? If the primary (input) voltage is 120, then at full load the transformer will draw about 0.42 A from the line, and the current delivered to the load depends on the secondary (output) voltage. If the secondary (output) voltage is 120, then at full load the transformer will deliver about 0.42 A to the load, and the current drawn fom the line depends on the primary (input) voltage. amps = watts / volts So, for instance, if your transformer has a 120 V primary, and a 24 V secondary, as you might find in your AC unit or furnace: Primary current (at full load) - A = W / V A = 50 / 120 A = 0.4166 Secondary current - A = 50 / 24 A = 2.08

Depending on the type of DC motor, it will either run normally or just heat up and make noise.
i think the motor will rotate to and frow.means it will rotate in clycle.it will complete half cycle.and after it will complete its other half cycle in anticlockwise direction.

A: Actually it begins to conduct almost as soon as there available current. but the current is such a low value that it is considered not to be conducting at all. And the 0.7 volts drop is a chosen value to indicate that the diode is fully conducting and the voltage drop across is .7 volts there about. It can have any value lower then that and it all depends on the current flowing at the time.

The current input (primary) to a transformer is proportional to the output (secondary) current.

Differential protection relays monitor these via current transformers (CT).

The percentage of difference between primary and secondary can be adjusted.

If it is over the seting the relay will trip the primaryand secondary feeder breakers.

Thus indicating an inbalance between internal phasewindings and or shorts to earth.

A megohm is 1000 kilohms.

So 295k is 0.295M

They may or may not be required for all living spaces where you live when upgrading the panel. Call your local inspector to find out. In my area they are not required on an upgrade but I always install them in bedrooms, closets, living rooms, den, sun room, breakfast room, dining room, libraries, any place people gather may require them. AFCIs will not be required in bathrooms, kitchens, laundry rooms, unfinished basements, garages, attics or outdoors. I personally install them when I upgrade a service panel. They are a great safety device that will protect the people living in that home. I also recommend and install GFCI outlets where needed if the homeowner agrees.

The voltage is OK, but certain types of motor can't be run on the wrong frequency. If the appliance uses a commutator motor, like many hand tools, it would probably be OK.

Soldering SilverNo, it isn't hot enough. IT DEPENDS, if two silver plates are overlapped and then soldered with say electical (Tin/Lead) ie Resin cored solder then YES. But if two silver rods or bars or sheet are to be joined end to end etc then NO. The criteria is STRENGTH of the joining material and of course the COLOUR of the joint. THE process is as follows; Use a very hot Mini- Blow Torch ie. Butane or Propane torch, or Oxy- Propane welder and obtain High Silver content Silver Brazing rods (about 20%to 40% silver content) from Model engineering suppliers or Welding suppliers, and Practice first joining small peices of Brass or Copper. The best Silver brazing rods for your purposes are the FLUX-COATED types. EXPERIENCE AND PRACTICE WILL MAKE YOU VERY PROFICIENT.

Yes, if you buy a special type of solder. You can buy different solders for different metals or for different heat levels. Just go to your local hardware or a crafting or hobby store to buy these. The people there can offer great advice on whatever project you are doing.

Single-phase power transmission requires a live and a return wire, so power is lost due to current flowing through two wires for each (there is one) driving EMF.

If you add two more at 120 and 240 degrees (one and two thirds of a period), then you get three-phase power. Now, the sum of all currents at either end is zero. When one phase's voltage is high, the resulting current travels down that conductor and returns via a combination of the other two; but these other two currently have a voltage causing that exact same current (split in varying proportions between them) to flow, meaning this current can be considered not to be a "return" of the first phase. You could consider it getting a return conductor "for free".

you would have to put some type of resistor in the circuit with the motor...the resistor would have to be in series with the motor and would have to be of a high enough value to lower the voltage by 9 volts....There is a formula for working this out but you would need the amperage of the motor to figure this....

Some examples of disease spread through indirect contact and agents are as follows; Bacteria. E.coli causes food poisoning and urinary tract infections. Mycobacterium tuberculosis causes tuberculosis.

Viruses Influenza virus causes 'flu'. Herpes simplex virus causes herpes.

Protozoa Plasmodium causes malaria.

Fungi Tinea causes ringworm.

You need to get an electrician to put in a proper grounding rod. You don't want to become the path to ground and it sounds like that may be possible if unlikely with you current grounding situation. The problem may manifest itself else where in your house, such as a shower for example. I saw this very problem with a faulty ground in Florida.