Home
Class 12
PHYSICS
An electron emitted by a heated cathode ...

An electron emitted by a heated cathode and accelerated through a potential difference of 2.0 kV, enters a region with uniform magnetic field of 0.15 T. Determine the trajectory of the electron if the field (a) is transverse to its initial velocity, (b) makes an angle of 30º with the initial velocity.

Text Solution

Verified by Experts

(a) Circular trajectory of radius 1.0 mm normal to B. (b) Helical trajectory of radius 0.5 mm with velocity component `2.3 xx 10^7 ms^(-1) ` along B
Promotional Banner

Topper's Solved these Questions

  • MOVING CHARGES AND MAGNETISM

    NCERT GUJARATI|Exercise EXERCISE|13 Videos

  • MAGNETISM AND MATTER

    NCERT GUJARATI|Exercise Additional Exercises|19 Videos

  • NUCLEI

    NCERT GUJARATI|Exercise ADDITIONAL EXERCISES|9 Videos

Similar Questions

Explore conceptually related problems

If the solenoid in Exercise 5.5 is free to tum about the vertical direction and a uniform hortzontal magnetic field of 0.25 T is applied, what is the magnitude of torque on the solenoid when its axis makes an angle of 30^@ with the direction of applied field?

An electron moves perpendicular to uniform magnetic field B, on a circle of radius r. Now, if magnetic field is made half of its initial value, what would be new radius of circular path ?

An X-ray tube, operated at a potential difference of 40 kV, produce heat at the rate of 720 W.Assuming 0.5% of the energy of incident electrons is converted into X-rays , calculate (i)The number of electron per second striking the target (ii)The velocity of the incident electrons .

A short bar magnet of magnetic moment m=0.32 JT^(-1) is placed in a uniform magnetic field of 0.15 T. If the bar is free to rotate in the plane of the field, which orientation would correspond to its (a) stable and (b) unstable equilibrium? What is the potential energy of the magnetic in each case?

(a) Estimate the speed with which electrons emitted from a heated emitter of an evacuated tube impinge on the collector maintained at a potential difference of 500 V with respect to the emitter. Ignore the small initial speeds of the electrons. The specific charge of the electron, i.e., its e/m is given to be 1.76 xx 10^(11) C kg^(-1) . (b) Use the same formula you employ in (a) to obtain electron speed for an collector potential of 10 MV. Do you see what is wrong ? In what way is the formula to be modified?

(a) Estimate the speed with which electrons emitted from a heated emitter of an evacuated tube impinge on the collector maintained at a potential difference of 500 V with respect to the emitter.Ignore the small initial speeds of the electrons.The specific charge of the electron ,i.e., its (e)/(m) is given to be 1.76xx10^(11)Ckg^(-1) (b) Use the same formula you employ in (a)to obtain electron speed for an collector potential of 10 MV.Do you see what is wrong ?in what way is the formula to be modified?

A cubical region of space is filled with some uniform electric and magnetic fields. An electron enters the cube across one of its faces with velocity v and a positron enters via opposite face with velocity – v. At this instant,

An electron enters with a velocity vecv,v_(0)hati into a cubical region (faces parallel to coordinate planes) in which there are uniform electric and magnetic fields. The orbit of the electron is found to spiral down inside the cube in plane parallel to the x-y plane. Suggest a configuration of fields E and B that can lead to it.

A magnetic field set up using Helmholtz coils (described in Exercise 4.16) is uniform in a small region and has a magnitude of 0.75 T. In the same region, a uniform electrostatic field is maintained in a direction normal to the common axis of the coils. A narrow beam of (single species) charged particles all accelerated through 15 kV enters this region in a direction perpendicular to both the axis of the coils and the electrostatic field. If the beam remains undeflected when the electrostatic field is 9.0xx10^(-5)Vm^(-1) , make a simple guess as to what the beam contains. Why is the answer not unique ?

A coil having 10 Am^2 magnetic moment is placed in a vertical plane & is free to rotate about its horizontal axis coincides with its diameter. A uniform magnetic field of 2T in the horizontal direction exists such that initially the axis of the coil is in the direction of the field. The coil rotates through an angle of 90^@ under the influence of magnetic field. The moment of Inertia of coil is 0.1 kg m^2 . What will be its angular speed?

NCERT GUJARATI-MOVING CHARGES AND MAGNETISM -ADDITIONAL EXERCISES
  1. Two concentric circular coils X and Y of radii 16 cm and 10 cm, respec...

    Text Solution

    |

  2. A magnetic field of 100 G (1 G = 10^(-4) T) is required which is unifo...

    Text Solution

    |

  3. For a circular coil of radius R and N turns carrying current I, the ma...

    Text Solution

    |

  4. A toroid has a core (non-ferromagnetic) of inner radius 25 cm and oute...

    Text Solution

    |

  5. A magnetic field that varies in magnitude from point to point but has ...

    Text Solution

    |

  6. A charged particle enters an environment of a strong and non-uniform m...

    Text Solution

    |

  7. An electron travelling west to east enters a chamber having a uniform ...

    Text Solution

    |

  8. An electron emitted by a heated cathode and accelerated through a pote...

    Text Solution

    |

  9. A magnetic field set up using Helmholtz coils (described in Exercise 4...

    Text Solution

    |

  10. A straight horizontal conducting rod of length 0.45 m and mass 60 g is...

    Text Solution

    |

  11. The wires which connect the battery of an automobile to its starting m...

    Text Solution

    |

  12. A uniform magnetic field of 1.5 T exists in a cylindrical region of ra...

    Text Solution

    |

  13. A uniform magnetic field of 0.3 T is established along the positive Z-...

    Text Solution

    |

  14. A circular coil of 20 turns and radius 10 cm is placed in a uniform ma...

    Text Solution

    |

  15. A solenoid 60 cm long and of radius 4.0 cm has 3 layers of windings of...

    Text Solution

    |

  16. A galvanometer coil has a resistance of 12 Omega and the metre shows...

    Text Solution

    |

  17. A galvanometer coil has a resistance of 15 Omega and the metre shows ...

    Text Solution

    |