Brock University
Physics Courses
Physics Department
Instructor: E.Sternin
Physics Courses
Physics Department
Instructor: E.Sternin
Usage: enter the values for up to five point charges in the
boxes on the right-hand-side, then select what you want to display
(grid, electric field E, electric potential U, and any combination) and
click Update. Charges are entered as triples of (q,x,y), to three
decimal places, with the allowed range of -8.00<q<8.00
and -2.50 < x,y < 2.50. Entering out-of-range values
is quietly ignored, and the last valid value is restored. Charges can also
be placed with a mouse, q=+1 for the left button, and q=-1
for the right. Units are arbitrary,
but are to scale. The size of the arrows (for E),
squares (for U), and circles (for q)
scales with the magnitude of the appropriate
physical quantity at a given point, although some liberties
were taken in the interest of display clarity.
Filled symbols (white for charges, blue for U)
represent positive values, and empty symbols represent negative values.
Physics:
the electric field E (red arrows) represents the force on a unit
positive test charge placed at that point, and is a vector.
The electric potential U (blue squares) is a scalar quantity,
a measure of the potential energy per unit charge, relative to a
zero chosen arbitrarily at a point infinitely far away from all charges.