Electrical Engineering

"50 Hz" is the shortened form of "50 hertz" which means "50 cycles per second".

50 Hz is the frequency of alternating current (ac) used by national electricity power services in many countries in Europe and elsewhere in the world whilst in USA, Canada and many other countries it is 60 Hz.

Summarizing

Can also be expressed as Kbps, Mbps, Gbps, etc.

Assuming that you are referring to a piece of equipment designed for 60-hz power being connected to a 50-hz power line (common overseas), It depends on the application. If the load is a DC power supply, they are often rated for both 50 and 60 hz. If the load is a motor made for 60 hz, for example, it will run about 17% slower at 50 hz than at 60 hz due to the design of induction motors, and at higher current because of lower inductive reactance. If the load is fluorescent lighting, it may display an annoying flicker, and the ballasts will probably die an early death. If the load is transformer-powered, you'll have the same current problems as you get with the motor. OTOH, if you want to connect a 50-hz load to a 60-hz supply, it has its own issues. E.g., the motor will run faster and cannot be loaded as heavily. Best bet: research to see if the piece of equipment is rated for both frequencies.

In electronic gears we use voltage bridging, that is a relative low output impedance to a higher input impedance. Usualy the input impedance is more than ten times higher then the output impedance.
An input impedance is called also a load impedance or an external impedance.
An output impedance is called also a source impedance or an internal impedance.

if resistors connected in series the resistance will increase.Then it limit the flow of current through it. voltage may be increased.

A: by connecting any resistors in series it will limit the current flow it will effect the current but never the voltage applied

A: The processes contains three basic functions, arithmetic's, controller, input/output

Three types of Mcbs

TypeA

TypeB

TypeC

A: FM means frequency Modulation meaning the frequency remain the same. pulse modulation the frequency can vary

• By using the star- delta starting method
• By using variable rhoestats
• By using auto transformers

A full-wave bridge rectifier with 4 diodes gives a dc output voltage equal to the average voltage of the whole transformer secondary. A FW rectifier with 2 diodes and a centre-tapped secondary gives an output voltage equal to the average voltage of half the secondary.

If you have a 12-0-12 transformer, the bridge gives a 24 v output, while the 2-diode FW rectifier gives 12 v (approximately).

This happens when the
voltage across and current through it are in phase (in step). Normally
any component that consists of a pure resistance (i.e. not having any
inductance or capacitance as a part of it) could be used as a resistive
load. There is however the special case where there are inductors and
capacitors in the load but their effect cancels out at certain
frequencies (e.g resonance).

Electrical resistance is just that: obstruction to the flow of electrons, which are (generally speaking) electric current. Electrons are what orbit the nucleus of an atom. You can force them out of their various orbital shells by using the proper voltage. Many non-conductive materials are not suitable for electron flow because they have a high resistance, e.g. glass. But if you send enough voltage through materials with high resistance the electrons will arc through the air across the top of the material. Note: You can, with a high enough voltage applied in a particular manner, cause the material itself to "fail" and conduct electricity. The high voltage will destroy the material when it ionizes the atoms within it. We can generate voltages high enough to punch through anything. Almost anything metallic is a good material for an electron to go through. In general, metals are good conductors of electricity. They have a low resistance.

If the OLTC is on the secondary, and the secondary voltage is high, the OLTC will tap down, which will lower the voltage. Typical range of OLTC is +/- 10%. The primary may also have multiple taps so the OLTC can be set at '0' under normal conditions.

When a resistance measurement is taken from both primary leads tied together to both secondary leads also tied together in a transformer, and the resistance obtained is 200 Ohms -- not safe in my book.

With a PLC the I/O is fixed when you buy it. Smaller stand alone units are hardwired with the exact I/O you are going to have. Even expandable configurations have a fixed input and output memory table. The PLC scans its Boolean algebra logic, constantly and sequentially, and compares that program to the I/O tables' inputs, outputs and relays. Then it makes its' decisions depending on their state.

Symmetrical components are a good way to represent out-of balance currents in 3-phase power supplies.

In general an unbalanced set of currents in a 3-phase system can be represented by three compents, which are an in-sequence component, an out-of-sequence (rotating oppositely) component, and a zero-sequence component.

At a high-power substation there would be meters for all three components of the current. When the currents are perfectly balanced only the positive sequence current would be non-zero.

secondary instruments are calibrated.absolute instruments are not calibrated.

secondary instruments are used everywhere,ab instru are only in labs or std institutions.

VOLKSWAGEN

I could not find anything mentioned in the 1997 owner's manual , but for 1995 and 1996 models they have as many as 3 auxillary relay boxes in the engine compartment (if you also have the automatic ride control - ARC) They are numbered 1 , 2 . + 3 but 1996 is not numbered the same as 1995.

The opposite of stomatal conductance of course!

false

If overload is not the cause, then high temperature could be caused by blocking the cooling of the motor.