Recharge Free Talk Time
Note: Daily You can earn Minimum Rs. 1.60 = Login Bonus(10 paise) + Play Trivia Game(50 paise) + Daily Humor(50 paise) + Vocabulary Builder(50 pasie)
Click Here To Register In Amulyam
Click Here To Register In Amulyam
Wednesday, August 28, 2013
Sunday, June 9, 2013
MAGNETIC PARAMETERS
1Q: What is meant by a unit pole?
Ans: If two poles are placed at one metre apart in vacuum and they exert a force of one newton on each other then each of them is known as unit pole.
2Q: How much magnetising force will be developed by a solenoid of 1 metres long having N turns with a current flow of I amperes?
Ans: Magnetising force, H = N.I/l ampere-turns.
3Q: What is meant by M.M.F.?
Ans: The force responsible for the production of magnetic field around a magnet is called M.M.F. or magneto-motive-force.
M.M.F. = N.I amp-turns.
where, N = Number of turns of the coil.
I = Current passing through the coil, in amperes.
4Q: What is meant by reluctance?
Ans: The opposite offered by a material to the production of magnetic field in that material is called reluctance. It is analogue to the resistance of an electrical circuit.
5Q: What is meant by retentivity?
Ans: The property of magnetic materials of retaining magnetism after withdrawal of the magnetising force is referred as retentivity.
6Q: What is meant by residual magnetism?
Ans: The quantity of magnetism retained by a magnetic material after withdrawal of the magnetising force is called residual magnetism.
7Q: What is meant by hysteresis?
Ans: The phenomenon of lagging of flux density behind the magnetising force is called hysteresis.
8Q: What is meant by coercivity?
Ans: The amount of magnetising force required to counter balance the residual magnetism of a magnetic material is referred as coercivity or 'coercive force' for that material.
9Q: What is meant by susceptibility?
Ans: The ability of a substance of getting magnetised is called susceptibility.
10Q: What is meant by magnetic axis?
Ans: The straight line passing through the two poles of a magnet is called magnetic axis.
11Q: What is a magnetic pole?
Ans: A magnetic pole is a point in a magnet where the intensity of magnetic lines of force is maximum.
12Q: What will happen if a magnet is broken into several pieces?
Ans: Each magnet piece will behave as an independent magnet.
13Q: What for the permanent magnets used?
Ans: Permanent magnets are used in small motors, magnetoes, loud-speakers, electrical measuring instruments etc.
14Q: What are the characteristics of an electromagnet?
Ans: (1) Its magnetic field strength can be varied by changing the magnitude of current.
(2) Its polarity can be changed by changing the direction of the current passed through its coil.
(3) Its magnetic field strength can be made thousand times greater in comparison to a permanent magnet.
(4) In many equipments and machines only electromagnets can possibly be used.
15Q: What is an electric bell?
Ans: An electric bell is an application of electomagnetism which is used as a call-bell in houses, offices, hotels etc.
16Q: What is a relay?
Ans: It is an electromagnetic device which can make 'on' or 'off' a number of circuits at a time at a specified voltage or current as per its design.
Ans: If two poles are placed at one metre apart in vacuum and they exert a force of one newton on each other then each of them is known as unit pole.
2Q: How much magnetising force will be developed by a solenoid of 1 metres long having N turns with a current flow of I amperes?
Ans: Magnetising force, H = N.I/l ampere-turns.
3Q: What is meant by M.M.F.?
Ans: The force responsible for the production of magnetic field around a magnet is called M.M.F. or magneto-motive-force.
M.M.F. = N.I amp-turns.
where, N = Number of turns of the coil.
I = Current passing through the coil, in amperes.
4Q: What is meant by reluctance?
Ans: The opposite offered by a material to the production of magnetic field in that material is called reluctance. It is analogue to the resistance of an electrical circuit.
5Q: What is meant by retentivity?
Ans: The property of magnetic materials of retaining magnetism after withdrawal of the magnetising force is referred as retentivity.
6Q: What is meant by residual magnetism?
Ans: The quantity of magnetism retained by a magnetic material after withdrawal of the magnetising force is called residual magnetism.
7Q: What is meant by hysteresis?
Ans: The phenomenon of lagging of flux density behind the magnetising force is called hysteresis.
8Q: What is meant by coercivity?
Ans: The amount of magnetising force required to counter balance the residual magnetism of a magnetic material is referred as coercivity or 'coercive force' for that material.
9Q: What is meant by susceptibility?
Ans: The ability of a substance of getting magnetised is called susceptibility.
10Q: What is meant by magnetic axis?
Ans: The straight line passing through the two poles of a magnet is called magnetic axis.
11Q: What is a magnetic pole?
Ans: A magnetic pole is a point in a magnet where the intensity of magnetic lines of force is maximum.
12Q: What will happen if a magnet is broken into several pieces?
Ans: Each magnet piece will behave as an independent magnet.
13Q: What for the permanent magnets used?
Ans: Permanent magnets are used in small motors, magnetoes, loud-speakers, electrical measuring instruments etc.
14Q: What are the characteristics of an electromagnet?
Ans: (1) Its magnetic field strength can be varied by changing the magnitude of current.
(2) Its polarity can be changed by changing the direction of the current passed through its coil.
(3) Its magnetic field strength can be made thousand times greater in comparison to a permanent magnet.
(4) In many equipments and machines only electromagnets can possibly be used.
15Q: What is an electric bell?
Ans: An electric bell is an application of electomagnetism which is used as a call-bell in houses, offices, hotels etc.
16Q: What is a relay?
Ans: It is an electromagnetic device which can make 'on' or 'off' a number of circuits at a time at a specified voltage or current as per its design.
Subscribe to:
Posts (Atom)
