Electrical Engineering

If 3 identical 45-ohm resistors are connected in parallel, the net effective resistance of the bunch ...
and the load seen by the battery ... is 15 ohms. The current supplied by the battery is

60/15 = 4 Amperes.

(This assumes that the battery is capable of supplying 4 amps at 60 volts, or 240 watts !)

zero

Because it is a metal so has lots of free electrons which when connected to a circuit detach from the atoms and move around the circuit. This produces a high current, so resistance will be low as current is high.

There is no need to place a 6 pole disconnect to isolate the motor in the field. The motor's leads at the motor's terminal box have to be wired for a delta connection. The star delta contactor in the MCC only has three wires on its output. Six wires do not have to be taken directly to the motor. The voltage is reduced at the start of the circuit when the starter in in the star configuration. From the star configuration it changes to the delta configuration. So as you can see only a three pole isolation switch is needed in the field to isolate the motor from its supply.

No, by itself a thermocouple can only measure temperature difference between two points (junctions) in a circuit. To use a thermocouple as a temperature sensor, you must know the temperature of one junction by some other means. Often an additional temperature sensor is used. However, in some applications temperature difference is enough. For example, in gas appliances a thermocouple detects presence of a flame because the flame is much hotter than room temperature-- you don't need to actually measure the flame temperature.

======================

Yes, it is. If you look up "thermocouple" in Wikipedia, you will find a very detailed

explanation of how and why they work.

If you have a circuit, the electrons will move through it and reach the negative terminal of, let's say, a battery. But if you have a direct line from the anode to the cathode, the electrons will ignore everything else, such as any LED's or motors you have on the circuit. In the case of electrical outlets, the cathode is unable to withstand as much electricity as the anode gives out. Also, this can cause an "arc" of ionized plasma to jump from the anode to the cathode, and I don't think you want to arc weld your electronics to the outlet...

The capacitance counter acts the inductivity (decreases it) without impacting the resistivivity, thus increasing the power factor, or resistivity / inductivity ratio.

karena kalau instal kabel terbalik, itu akan menyebabkan putaran motor jd terbalik... kalau putaran motor terbalik.. aktuator tdk dapat bekerja dengan semestinya (utk mengalirkan angin).

As the emf in an AC circuit causes current flow in the core of an inductor the magnetic dipoles will align themselves with the direction of the flow. As the current reverses the dipoles tend to stay aligned and there is a certain amount of flow that is required to realign them in the opposite direction. Thus there is a lag between current reversal and dipole realignment. The energy used for this realignment so to speak is called hysterisis and is a loss to the circuit.

If the voltage across a resistor or resistors is halved, then the resulting current will also fall by half.

You may be thinking of Fleming's Left-Hand Rule (for conventional current flow) or Fleming's Right-Hand Rule (for electron flow), devised by academic Sir Ambrose Fleming, as a aid for determining the direction of the resulting force acting on a current-carrying conductor within a magnetic field, when the direction of current and the direction of the magnetic field are known.

Current relays are the relay which sens the current passing in particular circuit and operates when this current exceed its set value.

Status October 2008

about 2200 hryven = $400 per month official salary

about 4000 Hrn. = $800 estimated unofficial salary

DRDO - Padamshri Dr. VK Saraswat appointed as new DRDO Head:eTI

it s the ratio of net cross section occupied by the magnetic material to the gross cross section of the core

generally, its value s between 0.5 to 0.95

Test equipment is calibrated against a standard of some sort that is stable. In many cases these standards are traceable to the standards at the National Institute of Standards and Technology (NIST) in Maryland.

The Ferranti effect is reduced by using shunt reactors and series capacitors.

Inductors are considered to be a load for reactive power, meaning that they will draw reactive power from the system. Capacitors are considered to be sourced of reactive power, they feed reactive power into the system. If you have a circuit that is at unity (balanced with inductors and capacitors) no reactive power will be drawn from the source. You will have unity power factor. If your circuit is more inductive than capacitive it will be drawing reactive power from the source. The opposite is also true for capacitors.

There are several examples of BEAM robots which are line followers. BEAM robotics uses simple logic chips for the "brain" like the 74AC240 which costs $1 or so. The rest of the components are discrete components which means no microcontrollers are involved - only the usual parts like diodes, resistors, capacitors etc. I've included 2 links in the "Related Links" section below.

Zero to 100 ohms.

There is no such thing as a 'phase conductor'; the correct term is 'line conductor'. In a single-phase system, the line conductor is the energised conductor; in a three-phase system, there are three (energised) line conductors.

10-32 unf-2a

<<>>

The wire size does not need to be calculated. Use a wire terminal end that crimps to the wire. These terminal end come in various wire sizes and bolt hole sizes. Pick the correct end for the wire size you are using and then in that wire size range, pick the correct bolt hole size that fits the bolt.