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The flux density of an electromagnet can be easily controlled. It's also easy and cheap to produce a large flux density with an electromagnet which is necessary for such large dc motors. Permanent magnets are generally expensive. For such a large motor,a very large permanent magnet will be needed for that motor which will not be ideal.
AnswerElectromagnets are more powerful than temporary magnets, and -as pointed out above- their flux density can be controlled.
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What of types of symbols would be used on an electrical drawing for a large machine?
c
What are the advantages of Swinburne's test?
1. swinburne's test is economical since power required to test a large machine is very small (i.e.,)no load input power. 2.The efficiency of the machine can be predicted at any load, since constant losses are known. 3.This method enables us to determine the losses and efficiency without actually loading the machine
Why is excitation necessary for synchronous generators?
generators work by rotating a magnetic field thru a wire shell or by rotating wire thru a stationary magnetic field (think of a small DC motor with magnets around the shell) since large generators dont have magnets in them (its not very efficent)you have to send a flowing current thru the rotating coils to produce the magnetic field. this induces current in the stator and you have a generator..of course the same effect is produced by inducing a current in the stator and pulling the output from the rotor.
What is thyristor based welding machine?
A thyristor-based welding machine is a type of welding equipment that uses thyristors—semiconductor devices capable of controlling high voltages and currents—to regulate the welding process. This technology allows for precise control of welding parameters such as current and voltage, improving the quality and consistency of welds. Thyristor-based machines are often used in arc welding applications, including TIG and MIG welding, due to their efficiency and ability to handle large power loads. They offer advantages like reduced energy consumption and enhanced welding performance compared to traditional machines.
What does 50db sound like?
Quiet street Normal conversation refrigerator 50 - 60 electric toothbrush 50 - 75 washing machine 50 - 75 air conditioner 50 - 80 electric shaver 40-45-hotel, theater between performances 50-65-loud conversation 40 quiet office, library 50 large office
Why is electromagnets better than permanent for collecting scrap iron?
Electromagnets can be turned on and off, allowing for easier control and manipulation of scrap iron. They can generate a stronger magnetic force than permanent magnets, making them more effective at attracting and holding onto large amounts of scrap iron. Additionally, electromagnets can be customized to vary the strength of the magnetic field as needed for different applications.
Where use electromagnets?
Electromagnets are used in various applications such as MRI machines in the medical field, speakers and headphones in audio devices, and electric motors and generators in industrial machinery. They are also used in magnetic levitation trains, particle accelerators, and in various electronic devices like relays and solenoids.
What are electromagnets used to record information on?
Electromagnets...electromagnets are magnets attract, or pull, some kinds of metal objects. Stronger magnets exert a greater pull on the objects they attract. Sometimes it would be useful if you could turn off a magnet when you did not want it to attract objects. That is what an electromagnet can do. Some electromagnets .in power plants and factories electromagnets are very large. You can make a small, simple electromagnet in school or at home.
Is an electromagnet stronger than a permanent magnet?
Not necessarily. The key difference between a permanent magnet and an electromagnet is the a permanent magnet does not change whereas an electromagnet's magnetic feild can be altered by varying the current through it. This means that electromagnets are more useful because they can be turned on or off, turned up or down or be put in 'reverse'.
How does a train move on magnets?
In the case of the maglev (magnetic levitation), the train has large electromagnets in its drive section, and the track has large electromagnets along the trackway. The electromagnets in the train are energized, and the ones in the trackway below the train are energized, and this both lifts and propels (and stops) the train. The magnets in the trackway are energized along the path of the train so no energy is being used in the trackway electromagnets except the ones right below and directly in front of the train. Use the provided link to the Wikipedia article and check things out.
How can a magnet lose it's magnetic?
Permanent magnets are magnetic because of things called "domains." Domains are like mini-magnets in the large magnet - when they all line up perfectly, you get a noticeable magnetic field. When they don't, the domains cancel each other out, and hence, do not create a magnet. To demagnetize a permanent magnet, the domains must come out of alignment - this is most easily accomplished by imparting a large force to the magnet (hitting it with a hammer) Alternatively, electromagnets are created via moving charges in a coil of wire (electric current). These magnets are designed to be turned on and off, so demagnetizing an electromagnet is as simple as switching off the current.
5 appliances that have magnets or electromagnets in them?
Refrigerators use magnets to seal the door shut and keep it closed. Microwave ovens have electromagnets in the magnetron to generate microwave radiation for cooking food. Washing machines use electromagnets in the motor to create rotational motion for agitating and spinning the drum. Electric fans and blowers have electromagnets in the motor to generate the rotating motion for air circulation. MRI machines use powerful electromagnets to produce detailed images of the body's internal structures.
How far does a magnetic field extend?
The extent of a magnetic field depends on the strength of the magnet producing the field. In general, the magnetic field of a permanent magnet extends a few times the physical size of the magnet. For electromagnets or large magnets, the field can extend several meters.
Can magnets lift up things?
Magnets are better used in lifting hot metals. Lifting magnets are the type of magnets that are used to lift high temperature magnetic materials.
Why is a crane in a steelworks fitted with a large electromagnet?
Because they can then lift the steel easily without having to put chains and lifting gear onto it.
What are the benefits of using an electromagnet rather than a bar manet?
An electro-magnet can be switched on & off - a bar magnet is 'permanent' Think of a scrap-yard. If the magnet they use to pick up huge quantities of metal were permanent, they'd have to manually remove every piece. With an electro-magnet, they simply turn the power on to pick up a load, and off when they want to release it. You can make your own electro-magnet with a battery, some wire and a large nail.
Do cars use magnets?
Most cars do not use many magnets, however, there were several experimental cars developed during the 1940s and being reexamined currently that actually run on large electromagnets. The main downfall of these cars is that they pulled down power lines and literally ripped cables up from under the road with their powerful magnetic field.
