Electrical Engineering

Primary winding carry more current.

We measure the current in one single wire, so no of turns are 1, in secondary the no of turns are higher. so, obviously it has higher voltage then this wire. so, finally as per the transformer rule the secondary carry lesser current than primary.

Similar to DC permanent magnet motor (which I'm assuming you understand); except the stator is not a permanent magnet but an electromagnet. There are 2 separate coils on the stator, which are connected in series with the brushes and armature:

supply ----- stator segment --- brush - armature - brush --- stator segment ----- return

Since the stator coil segments are wired in series with the armature, reversing the supply will *not* change the direction of rotation; as both magnetic fields will reverse together. (But a reversing switch affecting only the armature *will* reverse the rotation.) And since the motor will always turn in the same direction independent of the supply polarity, this means it will work equally well from DC or AC; and the supply frequency will not affect the rotation speed.

When it supplies a resistive load.

closed loop system

A megger would not be suitable for testing insulation resistance of a 13.2-kV transformer, as the transformer's voltage rating is significantly higher than the output voltage from a megger.

It depends on the frequency. At 60 Hertz, with an ordinary two pole synchronous motor, you cannot have an RPM that is greater than 1800, so a six thousand RPM motor has to have a different power supply.

Overhead lines have 'sag' (not 'slack') because the conductors need to be able to expand and contract as the temperature changes. If sag isn't built into the design of the line then, when the conductors contract, they will put undue lateral strain on the supporting poles or towers. It is important that, with maximum sag, the minimum clearance distance between the line conductors and the ground below is always maintained. This safety clearance increases, of course, with line voltage. Allowing for the necessary sag part of the design-process for any overhead line, and achieving it becomes the responsibility of the linesmen when the line is eventually constructed.

Restructuring the existing power system network to achieve better utilization of electrical energy with reduction of losses

non ohmic devices are diodes, LED's, Thermistors, LDR(light dependent resistors, cells in series.

A current shunt is a device with a very low resistance, usually around one ohm. The exact resistance of the shunt is printed on the device for reference, and it is often slightly higher or lower than nominal, for example a 1 ohm shunt may actually have a resistance of .99986 ohms or 1.0002 ohms. A current shunt is not used to control current, however, so I do not know if this is the device you are asking about. It is used to measure current by using a precision voltmeter to measure the voltage drop across the shunt, and then using ohms law to calculate the current. Voltage (Volts) divided by Resistance (Ohms) equals Current (Amps). When the shunt is placed so that it interrupts a circuit, (placed in series), the current flowing in the circuit can be accurately measured with the shunt, without changing the values in the circuit enough to affect it. Many shunts of this type have a large heavy duty resistor that does not overheat easily. The shunt should also have a max current rating listed on it.

The letter 'G' stands for 'giga' and its position represents the decimal marker. So, '5G' represents 5.0 gigaohms.

A single load doesn't really constitute either a series or a parallel circuit. You could argue that the lamp is in series with the supply, because the same current flows through both. But you could also argue that it is in parallel with the supply, as it shares the same voltage. So the terms 'series' and 'parallel' are only really used when to describe how two or more loads are connected to the supply.

yes i think so

Yes, there are flashing l.e.ds. An ordinary l.e.d. can, of course, be flashed on and off by interrupting the current through it. There are products such as the LED-FLASHDIM available from LED-SUPPLIES.COM that will enable you to control how LED strip lighting flashes and at what speed and brightness levels

it can not be use for heavy duty motors as well as it requires a high starting current.

In the UK, the letters, 'R-Y-B', stand for 'red-yellow-blue' which are the colours used to identify the lines (not phases) of a three-phase transmission or distribution cable. The colours are also used, in some cases, to identify the corresponding bushings for transformers, circuit breakers, voltage transformers (potential transformers), etc., in substations. The sequence of these letters/colours also correspond to the normal phase sequence of the three-phase system.

In UK residential, commercial, and industrial installations, these colours have now been replaced by the EU harmonisation colours: brown-black-grey.

Other countries use different methods of identifying line conductors, including 1-2-3, A-B-C, R-S-T, L1-L2-L3, etc., or various combinations of these methods.

Surge diverters are normally located on the terminal pole of an overhead line system, and are intended to protect terminal equipment (e.g. transformers, cables, etc.) from sudden surges in voltage. Each of the line conductors is normally connected to earth, via the surge diverter.

Under normal circumstances, the internal resistance of the surge diverter is high enough to insulate the line conductor from earth. However, if a voltage surge occurs due, for example, to a lightning strike, then the resistance of the surge diverter will collapse, 'diverting' the surge to earth.

Take the internal series resistance of the voltage source and make it the internal parallel resistance of the current source. Then compute using Ohm's law the current of the current source to be equal to the maximum current the original voltage source could supply a short circuit load.

Note: the two sources are equivalent.

what is the value of the smallest division on a ammeter

No. The capacitor may improve its power factor by altering the effective reactive power of the machine, thus reducing the current drawn from the supply.

yes

A spur is an extension connected from some point along the main circuit of an electrical installation. Spurs are sometimes called 'tees'.