Charge in Electric and Magnetic Fields

  • In a magnetic field directed eastward a charged particle has its velocity directed northward at an instant. The center of the magnetic field is
    A) vertically below the initial position of the particle
    B) below and to the east of the initial position of the particle
    C) below and to the west of the initial position of the particle
    D) above and to the west of the initial position of the particle.
  • In a magnetic field directed at some angle above eastward horizontal a charged particle has its velocity directed northward at an instant. The center of the magnetic field is
    A) vertically below the position of the particle
    B) below and to the east of the position of the particle
    C) below and to the west of the position of the particle
    D) above and to the west of the position of the particle
  • A charged particle is located at the origin with its velocity directed along + y axis. Magnetic field in the region is directed 45° above the x axis in the xz plane. If R is the radius of the circular path of the charged particle in this magnetic field, The coordinates of the center of the magnetic field are
    A) $ R/√2,  R/√2, 0$ B) $ 0, R/√2,  R/√2$ C) $ -R/√2, 0,  R/√2$ D) $ R/√2, 0, -R/√2$
  • A charged particle has a northward velocity in a magnetic field directed vertically downward. At a certain instant an electric field directed vertically upward is switched on. The path of the particle is
    A) circle B) cycloid C) helix D) parabola
  • A charged particle has a northward velocity in a magnetic field directed vertically downward. At a certain instant an electric field directed vertically upward is switched on. The path of the particle is
    A) circle B) cycloid C) helix D) parabola
  • A charged particle has a northward velocity in a magnetic field directed vertically upward. An electric field directed eastward also exists in this region of space. The projection of the path is a circle in
    A) horizontal plane B) vertical plane containing north south
    C) vertical plane containing east west D) none of these
  • A charged particle has a northward velocity in a magnetic field directed vertically upward. An electric field directed upward also exists in this region of space. The projection of the path is a circle in
    A) horizontal plane B) vertical plane containing north south
    C) vertical plane containing east west D) none of these
  • A charged particle has a northward velocity in a magnetic field directed vertically upward. An electric field directed upward also exists in this region of space. Its path is
    A) a helix with constant pitch B) a helix with increasing pitch
    C) a circle D) a cycloid