What is a permanent magnet ?

1 Answer

Answer :

Even if a magnet is removed from the magnetic field, the magnetism does not disappear, so a permanent magnet.

Related questions

Description : How many poles of a magnet ?

Last Answer : : There are two poles of magnet 1) North pole 2) South pole.

Description : What does a magnet repel ?

Last Answer : Repel the homogeneous magnetic pole.

Description : What is the material for making artificial magnet ?

Last Answer : Synthetic magnets are made by supplying electric current to the cast iron. That means cast iron , wire and current are needed to make artificial magnets .

Description : What is a natural magnet ?

Last Answer : A magnet found in nature or in a mine is called a natural magnet. In the past, natural magnets were called loadstones

Description : What is an artificial magnet ?

Last Answer : Artificial magnets are magnets that are made in the laboratory using different magnets that are suitable for human work.

Description : What is a temporary magnet ?

Last Answer : : When a magnet is inserted into a field, it becomes a magnet .

Description : What is the meaning of religion of magnet ?

Last Answer : The poles of a magnet repel each other and the opposite poles attract each other. This is the religion of magnetism.

Description : Is the idea of permanent magnet "free energy" generators impossible?

Last Answer : answer:It's hard to say. I've tried building a few myself with no avail. I have gotten close a few times though, and that's just tinkering around. The problem with permanent magnets in a ... com/watch?v=bssBAb6EzM4&feature=related This one looks like it works, but was later revealed to be a hoax.

Description : What does a permanent magnet repel? -Do You Know?

Last Answer : answer:

Description : Which of the following iron and steel is used to make a permanent magnet ?

Last Answer : Steel is used between cast iron and steel to make permanent magnets.

Description : Which is the most permanent strong magnet ?

Last Answer : The most durable strong magnet is nickel.

Description : When a piece of iron rod is brought near a permanent magnet for a while it becomes magnitised by?

Last Answer : Need answer

Description : What does a permanent magnet repel?

Last Answer : – Diamagnetic substances only

Description : Permanent magnet is normally made of- (a) Aluminum (b) Wrought iron (c) Cast iron (d) Alnico alloys

Last Answer : Ans: C

Description : Which of the following electric meter movements uses a stationary permanent magnet and movable coil? A. D'Arsonval B. Electrodynamometer C. Moving iron-vane D. Inclined coil iron-vane

Last Answer : Answer: A

Description : The timer element of a reverse power relay cannot be energized unless _____________. A. the power flow is the same as the tripping direction B. the power flow is the opposite to the tripping direction C. the movement of the disk is damped by a permanent magnet D. one generator is motorized

Last Answer : Answer: A

Description : The timer element of a reverse power relay cannot be energized unless _____________. A. one generator is fully motorized B. the movement of the disk is damped by a permanent magnet C. the power flow is the same as the tripping direction D. the power flow is the opposite to the tripping direction

Last Answer : Answer: C

Description : What does a permanent magnet repel?

Last Answer : D i a m a g n e t i c substances only

Description : Magnetic field can be produced by using A. permanent magnet B. electric current C. temporary magnet D. both A and B

Last Answer : permanent magnet

Description : What is the difference between a temporary and a permanent magnet?

Last Answer : A piece of steel or iron which keeps magnetic properties is called a permanent magnet. When piece of iron becomes magnetized when it is touched by magnet, which means magnetism has been induced in it. ... away from the magnet, it loses its magnetism. This type of magnet is called a temporary magnet.

Description : The working of a meter is based on the use of a permanent magnet. In order to protect the meter functioning from stray magnetic fields (a) meter is surrounded by strong magnetic fields (b) a soft ... is used (c) a plastic shielding is provided (d) a shielding of anon-magnetic material is used

Last Answer : (b) a soft iron shielding is used

Description : What is the device, which depends on the action of a movalbe permanent magnet, in aligning itself in the resultant field produced by a fixed permanent magnet or current- carrying coils whose axes are displaced by a fixed angle?

Last Answer : moving-magnet instrument

Description : Permanent-magnet moving coil instrument can be used in

Last Answer : dc work only

Description : What is the reason why the scale of a permanent-magnet moving coil instrument is uniform?

Last Answer : because it is spring controlled

Description : The most suitable metal for making permanent magnet is a) Iron b) Steel c) Silver d) Copper

Last Answer : a) Iron

Description : Magnetic flux linked with a coil can be changed by using an: a. Permanent magnet b.Bar magnet c. Electromagnet d. Horseshoe magnet

Last Answer : b.Bar magne

Description : In motor a permanent magnet provides: a. Electric field b. electric flux c. magnetic field d. gravitational field

Last Answer : d. gravitational field

Description : The coating on the plastic tape you use in your cassette players is w) diamagnetic x) paramagnetic y) ferromagnetic z) a permanent magnet

Last Answer : ANSWER: Y -- FERROMAGNETIC

Description : Permanent Magnet Moving Coil (PMMC) Instrument

Last Answer : Permanent Magnet Moving Coil (PMMC) Instrument

Description : A permanent magnet moving coil instrument gives full scale deflection of 25mA when a voltage of 75mV is applied across it. Calculate: (i) Resistance of shunt required for full scale deflection of 150 A. (ii) Series resistance for full scale deflection of 500 V.

Last Answer : Answer :

Description : (i) Explain the working principle of Electrostatic and permanent magnet speaker. (ii) Compare Woofer and Tweeter.

Last Answer : (i) Electrostatic speaker. The voltage is applied to the central or movable plate, the signal voltage is applied to the two outside plates causes these plates to attract or repel each other. ... to minimize the impact of this resonant frequency. (ii) Compare Woofer and Tweeter.

Description : Compare variable reluctance and permanent magnet motors.

Last Answer : Variable reluctance Motor  Permanent magnet motors   The rotor is not magnetised The rotor is magnetised  High torque to inertia ratio  Low torque to inertia ratio  ... rotor has salient pole construction The rotor has mostly smooth cylindrical type of construction. 

Description : Name the material used for :- (i) Moving coil (ii) Permanent magnet in PMMC instrument.

Last Answer : (i) Material used for Moving coil: Copper, Aluminum( some times)  (ii) Permanent magnets are made of special alloys such as :  Aluminum-Nickel-Cobalt (Alnicos)  Strontium-Iron  Neodymium-Iron-Boron  Samarium-Cobalt.

Description : What is permanent magnet and electromagnet?

Last Answer : Permanent magnet: A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. As the name suggests, a permanent magnet is 'permanent'. ... an electric current passes through the coil. If the current is interrupted, the magnetism is lost.

Description : Write one application of each: i) Permanent Magnet ii) Electromagnet 

Last Answer : i) Applications of Permanent Magnet: 1) Field of DC motors 2) Tacho-generators 3) In stepper motors. 4) Field of two wheeler and car dynamo 5) In magnetic therapy 6) ... Motors, Generators, Transformers, Electromagnetic Relays, Circuit breakers, Traction, Measuring instruments, Electrical Bell etc.

Description : A permanent magnet moving coil ammeter has a coil resistance of 99 ohm and Full Scale Deflection (FSD) current of 0.1mA. Shunt resistance is 1 ohm. Current through the meter at 0.5 F.S.D is:

Last Answer : A permanent magnet moving coil ammeter has a coil resistance of 99 ohm and Full Scale Deflection (FSD) current of 0.1mA. Shunt resistance is 1 ohm. Current through the meter at 0.5 F.S.D is: 0.05mA

Description : The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 ... .5 A from the same source will be  (A) 48.0% (B) 57.1% (C) 59.2% (D) 88.8%

Last Answer : The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 48.0%

Description : The following motor definitely has a permanent magnet rotor  (A) DC commutator motor (B) Brushless dc motor (C) Stepper motor (D) Reluctance motor

Last Answer : The following motor definitely has a permanent magnet rotor Stepper motor

Description : Permanent magnet moving coil instruments are used for

Last Answer : PMME are mostly used for measuring voltage and current.

Description : A neodymium magnet is a permanent magnet made from an alloy of _________ A) Neodymium and iron B) Neodymium, iron and iodine C) Neodymium and boron D) Neodymium, iron and boron

Last Answer : A neodymium magnet is a permanent magnet made from an alloy of Neodymium, iron and boron

Description : The main purpose of permanent magnet motors are (A) to avoid the need for field supply (B) to provide high flux density (C) to provide control over flux level (D) to facilitate kW rating

Last Answer : The main purpose of permanent magnet motors are to avoid the need for field supply

Description : A permanent magnet stepper motor with 8 poles in stator and 6 poles in rotor will have a step angle of (a) 7.5° (b) 15° (c) 30° (d) 60°

Last Answer : d

Description :  The main sources of Errors in Permanent Magnet moving Coil (PMMC) are due to : - a) weaking of the permanent magnet due to aging at temperature effects b) weaking of spring due to aging and temperature effects c) change of resistance of the moving coil with temperature d) all the above

Last Answer :  The main sources of Errors in Permanent Magnet moving Coil (PMMC) are due to : - a) weaking of the permanent magnet due to aging at temperature effects b) weaking of spring due to aging and temperature effects c) change of resistance of the moving coil with temperature d) all the above

Last Answer : A permanent magnet attracts some substances and repels others.

Description : The working of a meter is based on the use of a permanent magnet. In order to protect the meter functioning from stray magnetic fields

Last Answer : The working of a meter is based on the use of a permanent magnet. In order to protect the meter functioning from stray magnetic fields a soft iron shielding is used.

Last Answer : Preferred material for permanent magnet is: Alnico

Last Answer : A moving-coil permanent-magnet instrument can be used as flux-meter by eliminating the control springs.

Last Answer : A moving-coil permanent-magnet instrument can be used as ammeter by using a low resistance shunt.

Description : Advantages and Disadvantages of Permanent Magnet Brushless DC (PMBLDC) Motor

Last Answer : Advantages and Disadvantages of Permanent Magnet Brushless DC (PMBLDC) Motor

Description : What is the conductivity of molar ?

Last Answer : The density of a solution as cm. When one mole of electrolytic substance is dissolved in it, the conductivity obtained by multiplying it by the relative conductivity of the solution is called molecular conductivity of the solution .