Standard electrocardiography measures time-dependent...

Standard electrocardiography measures time-dependent potential differences between multiple points on the body, giving cardiologists multiple perspectives on the heart's electrical activity. In contrast, Fig. 22.26 is a "snapshot" showing a more detailed picture at an instant of time. The lines are equipotentials on the surface of a human torso, associated with the heart's electrical activity. Relative to the line marked $V=0,$ the potential is negative to the upper left (black) and positive to the lower right (color). The electric field is strongest in the region marked a. $A$ b. $B$ c. $C$ d. $D$

Standard electrocardiography measures time-dependent potential differences between multiple points on the body, giving cardiologists multiple perspectives on the heart's electrical activity. In contrast, Fig. 22.26 is a "snapshot" showing a more detailed picture at an instant of time. The lines are equipotentials on the surface of a human torso, associated with the heart's electrical activity. Relative to the line marked $V=0,$ the potential is negative to the upper left (black) and positive to the lower right (color).
The electric field is strongest in the region marked
a. $A$
b. $B$
c. $C$
d. $D$

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Electric Field and Its Gradient

The electric field is related to the spatial change in electric potential by the gradient, with the field’s magnitude equal to the steepness of the potential change. Specifically, it is mathematically defined as the negative gradient of the electric potential. This means that the electric field is strongest where equipotential lines are closest together, indicating a rapid change in potential over a small distance.

Electric Potential

Electric potential is a scalar quantity that represents the electric energy per unit charge at any point in a field. It is defined so that the difference in potential between two points relates directly to the work done by the electric field when moving a charge between those points. In many practical applications, such as in medical imaging, this potential is used to infer details about underlying electrical activity.

Equipotential Lines

Equipotential lines are contours or surfaces over which the electric potential remains constant. They provide a map of equal voltage levels and are useful in visualizing how the potential is distributed in space. These lines help in understanding the geometry of the electric field, because the field must be perpendicular to these lines.

Transcript

Please give Ace some feedback