Concept explainers
In Figure 24.1, two points Ⓐ and Ⓑ are located within a region in which there is an electric field. (i) How would you describe the potential difference ΔV = VⒷ − VⒶ? (a) It is positive. (b) It is negative. (c) It is zero. (ii) A negative charge is placed at Ⓐ and then moved to Ⓑ. How would you describe the change in potential energy of the charge–field system for this process? Choose from the same possibilities.
Figure 24.1 (Quick Quiz 24.1) Two points in an electric field.
(a)
Answer to Problem 25.1QQ
Explanation of Solution
The point B is the point in the electric field having lower potential value as compared to the potential value of point A. Thus, the potential difference
Conclusion:
The potential difference between the points A and B is negative as the potential of point B is at the lower value. Thus, option (b) is correct.
The potential difference between the point A and B cannot be positive because the potential of point B is at the lower value. Thus, option (a) is incorrect.
The potential difference between the point A and B cannot be zero because the potential of point B and point A is not equal to each other. Thus, option (a) is incorrect.
(b)
Answer to Problem 25.1QQ
Explanation of Solution
The point B is the point in the electric field having lower potential value as compared to the potential value of point A. The potential difference between the points A and B is negative. The change in the potential energy is
Conclusion:
Therefore, the change in potential energy of the charge-field system is positive if a negative charge is paced at point A and then moved to B. Thus, option (a) is correct.
The change in potential energy of the charge field potential cannot be negative because the movement of negative charge led to change in potential energy for the positive. Thus, option (b) is incorrect.
The potential difference between the point A and B cannot be zero because the potential of point B and point A is not equal to each other. Thus the change in potential energy of charge field cannot be zero. Thus, option (c) is incorrect.
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Chapter 25 Solutions
EBK PHYSICS FOR SCIENTISTS AND ENGINEER
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