02 June 2012

X Physics: Magnetic effects of current important solve questions

X Physics: Magnetic effects of current

Q. If the magnetic field and the direction of movement of conductor is parallel, then in what direction does the induced current flows ?

Ans: The directions of current, field and force are always perpendicular to each other on account of the Fleming's rule, none of them can be parallel.

Q. If the direction of current and magnetic field is parallel the in which direction does the force on the conductor acts?

Ans: The directions of current, field and force are always perpendicular to each other on account of the Fleming's rule, none of them can be parallel.

Q. Consider a circular loop of wire lying in the plane of the table and current is passed thru the loop clock wise then by applying right hand rule find the direction of magnetic field lines inside and outside the loop?

Ans: According to the right hand thumb rule, the direction of the magnetic field would be perpendicular to the plane of the table and pointing downwards, into the plane.

Q. why two magnetic field lines do not intersect each other?



Ans: if the magnetic field lines will intersect then at that point the magnetic field will have two directions, which is not possible

Q. why does a compass needle get deflected when brought near a bar magnet ?

Ans: A magnetic compass aligns along the direction of the magnetic field of a bar magnet So, the compass needle shows deflection when brought near a magnet or an electromagnet.

Q. what is solenoid?

Ans: 'The solenoid is a long coil containing a large number of close turns of an insulated wire'. This is a coil wound in the shape of a helix. The magnetic field produced by a current carrying solenoid is similar to the magnetic field produced by a bar magnet.

The right hand thumb rule indicates the direction of magnetic field for a know direction of current. If the thumb of the right hand points along the direction of current then the curled fingers of that hand gives the direction of the magnetic field due to the current.

When thumb is upwards the curled fingers are anti-clockwise. So, magnetic field is anti-clockwise.

When thumb is downwards the curled fingers are clockwise. So, magnetic field is clockwise.

2 comments:

  1. Moving part of Electric motor
    • Two halves of the split rings are fixed on axle.
    • Split rings are made up of good conductor.
    • Inner side of split ring is insulated so that there is no current in axle.
    • Each of the halves of the split ring is joined permanently to end of the coils. (AB end connected to P Split ring, and CD end connected to Q Split ring)

    ReplyDelete
  2. Principle of Electric Motor
    • When a current-carrying conductor is located in an external magnetic field perpendicular to the conductor, the conductor experiences a force perpendicular to itself and to the external magnetic field.

    ReplyDelete

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