Home
Class 12
PHYSICS
Sometimes we show an idealised magnetic ...

Sometimes we show an idealised magnetic field which is uniform in a given region and falls to zero abruptly. One such field is represented in figure . Using Ampere's law over the path PQRS, show that such a field is not possible.

Text Solution

Verified by Experts

We know `int B dl = mu_oi`
Theoretically , at any point a inside
B = 0
If current passes through the loop PQRS
Then =0
As B at A is zero, so there will be no
interaction, but pracitcally this is not ture.
Thus, such a field is not possibal.
Promotional Banner

Topper's Solved these Questions

  • MAGNETIC FIELD DUE TO CURRENT

    HC VERMA|Exercise Objective 2|7 Videos

  • MAGNETIC FIELD

    HC VERMA|Exercise Exercises|61 Videos

  • MAGNETIC PROPERTIES OF MATTER

    HC VERMA|Exercise Exercises|9 Videos

Similar Questions

Explore conceptually related problems

Which scientist showed that by changing magnetic field electric field can be obtained ?

The following figure shows the magnetic field of a magnet. At which point is the intensity of the magnetic field more ?

How we can know direction of magnetic field using Biot-Savart law ?

Which figure , out of the following, shows the magnetic field lines of a bar magnet ?

(a) Magnetic field lines show the direction (at every point) along which a small magnetised needle aligns at the point). Do the magnetic field lines also represent the lines of force on a moving charged particle at every point? (b) Magnetic field lines can be entirely confined within the core of a toroid, but not within a straight solenoid. Why? (c) If magnetic monopoles existed, how would the Gauss's law of magnetism be modified? (d) Does a bar magnet exert a torque on itsell due to its own field? Does one element of a current-carrying wire exert a force on another element of the same wtre? (e) Magnetic field arises due to charges in motion. Can a system have magnetic moments even though its net charge is zero?

The sides of a square shaped frame, Shown in the diagram are made of wires of resistances r_(1) and r_(2) The frame is places in a uniform magnetic field, which is perpendicular to the plane of figure and is increasing at a constant rate. The resistance that should be connected across the diagonal of frame, so that this wire is warmed up at greatest rate is given by R=(n r_(1)r_(2))/(r_(1)+r_(2)) . Find n.

In a region, steady and uniform electric and magnetic fields are present. These two fields are parallel to each other. A charged particle is released from rest in the region. The path of the particle will be a.......

Which law is useful to determine relation between current and magnetic fields due to it.

(a) A closed loop is held stationary in the magnetic field between the north and south poles of two permanent magnets held fixed. Can we hope to generate current in the loop by using very strong magnets ? (b) A closed loop moves normal to the constant electric field between the plates of a large capacitor. Is a current induced in the loop (i) when it is wholly inside the region between the capacitor plates (ii) when it is partially outside the plates of the capacitor? The electric field is normal to the plane of the loop. (c) A rectangular loop and a circular loop are moving out of a uniform magnetic field region (Figure) to a field-free region with a constant velocity v. In which loop do you expect the induced emf to be constant during the passage out of the field region? The field is normal to the loops.

Which among the curves shown in figure cannot possibly represent electrostatic field lines ?

HC VERMA-MAGNETIC FIELD DUE TO CURRENT-Exercises
  1. A piece of wire carrying a current of 6.00 A is bent in the form of a ...

    Text Solution

    |

  2. A circular loop of radius r carries a current i. How should a long , ...

    Text Solution

    |

  3. A circular coil of 200 turns has a radius of 10 cm and carries a curre...

    Text Solution

    |

  4. A circular loop of radius 4.0 cm is placed in a horizontal plane and c...

    Text Solution

    |

  5. A charge of (3.14 xx 10^-6) C is distributed uniformly over a circular...

    Text Solution

    |

  6. A thin but long, hollow, cylindrical tube of radius r carries a curre...

    Text Solution

    |

  7. A long, cylindrical tube of inner and outer radii a and b carries a cu...

    Text Solution

    |

  8. A long, cylindrical wire of radius b carries a current i distributed u...

    Text Solution

    |

  9. A solid wire of radius 10 cm carries a current of 5.0 A distributed un...

    Text Solution

    |

  10. Sometimes we show an idealised magnetic field which is uniform in a gi...

    Text Solution

    |

  11. Two large metal sheets carry surface currents as shown in figure . The...

    Text Solution

    |

  12. Consider the situation of the previous problem. A particle having char...

    Text Solution

    |

  13. The magnetic field B inside a long solenoid, carrying a current of 5.0...

    Text Solution

    |

  14. A long solenoid is fabricated by closely winding a wire of radius 0.5 ...

    Text Solution

    |

  15. A copper wire having resistance 0.01 ohm in each metre is used to wind...

    Text Solution

    |

  16. A tightly- wound solenoid of radius a and length l has n turns per uni...

    Text Solution

    |

  17. A tightly- wound , long solenoid carries a current of 2.00 A. An elect...

    Text Solution

    |

  18. A tightly-wound, long solenoid has n turns per unit length, a radius r...

    Text Solution

    |

  19. A tightly- wound, long solenoid is kept with its axis parallel to a la...

    Text Solution

    |

  20. A capacitor of capacitance 100 mu F is connected to a battery of 20 vo...

    Text Solution

    |