Physics 1B
Thermal Physics & Electromagnetism

H. E. Smith Fall 2002

  Physics 1B - Reading Quiz #4
  1. In the hydrogen atom we find that the electrical force between the electron and proton is almost 1040 times greater than the gravitational force. Is there a finite distance between the particles such that the electrical force equals the gravitational force?
    • A. Yes, if we move them much closer together.
    • B. Yes, if we move them much farther apart.
    • C. No, because the electrical and gravitational forces have the same distance dependence.

  2. An electric dipole is placed at +/- x0 on the x-axis as shown below. What will be the direction of the resultant electric field at point P on the y-axis?
    • A. in the +x direction (parallel to the x-axis).
    • B. in the +y direction.
    • C. in the -x direction.
    • D. in another direction.
    • E. The E-field at P is zero.