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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
Where can one buy electric cooktops that use induction heating?
One can buy electric cooktops that use induction heating at most department stores that sell major appliances. Some stores are Lowes, Belk, and Sears.
How do you connect energy meter in circuit?
pressure coil or voltage coil across the supply and the current coil in series.
What happens to the speed of an induction motor if the supply frequency is increased?
The supply frequency determines the synchronous speed of the machine -i.e. the speed of the naturally-rotating field within the airgap. As motors typically run around 5% below this speed, the rotor's speed would increase.
Is there more current in the primary or secondary winding of a transformer?
The terms, 'primary' and 'secondary', describe how a transformer is connected and his nothing to do with which is the lower- and higher-voltage winding.
The primary winding is the winding connected to the supply, while the secondary winding is the winding connected to the load. So, for astep-up transformer, the secondary winding is the higher voltage winding, whereas for a step-down transformer, the secondary winding is the lower voltage winding.
For a loaded transformer, i.e. a transformer whose secondary is supplying a load, the higher-voltage winding carries the smaller current, while the lower-voltage winding carries the higher current.
Are fuses and circuit breakers designed in a way to protect people from shocks?
No. Well, not directly anyway. Fuses and circuit breakers are designed to protect electrical equipment, not persons, from damage due to overcurrents (overload currents or fault currents). By disconnecting such equipment, they are rendered safe. But the level of overcurrent that will trip a circuit breaker or cause a fuse to operate is usually significantly higher than the current that will cause electrocution. Anyone relying on a fuse of circuit breaker for personal protection is likely to be dead before that protective device operates!
To protect people, there are special devices called 'residual current devices' (UK terminology) or 'ground-fault interrupters' (North-American terminology) which will quickly disconnect at very low values of currents -below those which will cause electrocution. Such devices or, rather, their features are sometimes incorporated into circuit breakers so that such circuit breakers will protect both equipment andpersons. Often, these devices supply circuits that terminate in outdoor socket outlets (receptacles), so that electrical tools, such as lawn mowers, strimmers, etc., can be used safely.
For more information on how these devices are used, you should consult your country's electrical wiring regulations, as the requirements vary from country to country.
No country distributes electrical energy to homes or industry as d.c., but many country use high-voltage d.c. transmission systems -particularly for long-distance transmission (lower losses than a.c.), or for interconnecting independent grid systems (no synchronisation problems), or for undersea cables (no reactive currents),
The purpose of a Cobra inverter is what?
A Cobra power inverter changes direct current (DC) to alternating current (AC). It takes battery power and inverts it so that common household appliances can use the power.
How does voltage and resistance behave in a series and a parallel circuit?
The current through each resistor is equal to the voltage across it divided by its resistance for series and parallel circuits.
The expression that relates emf potential current and resistance is Ohm's law?
Yes, that is what it is called.
There is no such thing as a 'phase conductor'. The correct term is 'line conductor'. Line conductors are the three energised conductors that supply a three-phase load.
What is the advantage of using network reduction in electrical circuits?
It makes the calculation of currents and voltages easier.
What does a particular point of a line on a phase diagram represent?
The melting point or boiling point ...................
Why Ac voltage supply in your home has a magnitude 220V and frequency 50 Hz?
Different countries have made different decisions on the voltage and frequency of the electricity supply. A standard is necessary in each country to allow electrical equipment to be manufactured economically. Frequencies of 50 or 60 Hz are the only two standards used, and the nominal voltages vary from 100 v to 240 v for domestic supplies.
How do you use ohm's law to determine the current flowing through a 45 ohm resistor at 1.4 amps?
The current is 1.4 amps, as already stated. The voltage is 45 x 1.4 volts.
Why Y phase is high in YNyn0 when doing magnetic balance test?
because y phase is y phase ...it is not b phase or R phase so it is high
What is the efficiency of a 172.5Watt heater which draws 2A from a domestic supply?
Heaters have an efficiency around 99%.
What are convectional and non convectional methods of speed control of a induction motor?
The flux control method is the convectional and the non-convectional method of speed control of an induction motor.
What happens when more than rated voltage applied to transformer?
It will produce excessive magnetic flux in the core, which will lead to heating, even on no-load.
What is the purpose for generator synchronising?
The purpose for generator synchronizing is to match the speed and frequency.
In Europe, where the voltage is 230 v (nominally), hand tools used on building sites commonly use a 110 v centre-tap supply for safety, with the centre-tap earthed so the maximum voltage to earth is 55 v.
Portable transformers with two 16-amp output sockets are often used and they can be found for about £30.
What is power cable size for 1 kw 1 phase motor over 500 meters?
It depends on the voltage that the motor needs, because a higher voltage requires less current for a given amount of power. Also a higher voltage can tolerate a higher voltage drop. So there are two things that lead to a thinner wire when the voltage is higher.
How much current will 5 kva ups draws while charging?
- For a single phase supply @ 220 volts
current drawn by 5kva UPS = 22.7 amperes (at full load.)
