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A student wanted to determine if the electric potential varied inversely as the

ID: 1969045 • Letter: A

Question

A student wanted to determine if the electric potential varied inversely as the square of the distance in a non-uniform field. The following data was collected.

Distance of Test charge from Source Charge

(m)

Electric Potential

(x104 V)

100

27.0

200

13.5

300

8.99

400

6.74

500

5.39

600

4.49

Analyze the above data for two sets of numbers and determine if the electric potential varies inversely as the square of the distance in a non-uniform field.

Distance of Test charge from Source Charge

(m)

Electric Potential

(x104 V)

100

27.0

200

13.5

300

8.99

400

6.74

500

5.39

600

4.49

Explanation / Answer

If this were an inverse square relationship, the value at 200 would be (100/200)^2 * the value at 100, or 1/4 the value at 300 m it would be 1/9 at 400 m it would be 1/16 etc... We can see that the value at 200 is 1/2 of the value at 100 and the value at 300 is 1/3 the value at 100 etc... So we can determine that the electric potential varies inversely on a linear basis, not the square of the distance.