Physics 1bl Electric Potentials And Fields printable pdf download

Physics 1bl Electric Potentials And Fields

Physics 1BL

Electric Potentials & Fields

Summer Session II 2010

Pre-Lab Activity

The diagram represents a contour map of a hilly

island. Copy it into your lab notebook. The outer

contour of the figure is at sea level. All points on

any one particular contour line are at the same

elevation (vertical distance above sea-level). The

distance between any two contour lines in the

diagram represents the horizontal distance

between points on the two different contours.

North is up.

1. Each contour line as you go inland represents

ground that is at a constant elevation 5 meters

higher than the previous contour.

a) At what points on the map are there steep cliffs? Show at least three places.

b) There are two high areas, label the eastern one A and the western one B. How high

are they?

c) Mark a straight-line path to climb from sea level to the high point B with the most

gentle slope.

d) You are interested in how much work it takes to lift your body mass from sea level

to the B peak. If you follow the path you chose in part c) will you minimize the

amount of work to climb to the top, or will it make no difference?

2. The same diagram could also represent the contours of the electrical potential of two

positively charged objects with irregular shapes (for example charges stored on a rubber

sheet). Assume that the outer part of the figure is at zero potential. Each contour line

going towards the center represents an equipotential surface with a potential 5 V greater

than the previous contour.

a) Where is the electric field particularly strong? Show at least three places. Explain

your reasoning with reference to Q1(a).

b) There are two areas of high potential on the diagram. What is the value (in Volts) of

each of these high potential peaks?

c) What path would require you to use the least amount of force to push a test charge

from zero potential to the point of highest potential of one of the charged objects?

(Choose the same one you labeled B in 1b) above.) Explain your reasoning.

d) Would you actually do less work to move the test charge from 0 V to the voltage at

B by using the path selected in 2c), or would the actual path make no difference?

–7

3. Charges of +8.4x10

C each are located at three of the corners

–6

of a square that is 1.0 m on each side. A charge of –2.1x10

is located at the other corner. What is the electric field at the

center of the square (magnitude and direction)? What is the

electric potential at the center of the square?

Physics 1bl Electric Potentials And Fields

Related Articles

Related forms

Related Categories