Review Suppose you want to use a small, positively charged ball suspended by a light thread to map out the electric field in the space around a charged source. Describe the reaction of the ball as you place it at the two locations in front of the infinitely large, positively charged sheet shown in Figure P31.2A. Be sure to relate your description to what you know about the sheet’s electric field.
The reaction of the ball at the two different locations.
Answer to Problem 2PQ
The ball will deflect same in both the cases.
Explanation of Solution
Write the expression for the electric field due to a infinite sheet of charge as.
Here,
Write the expression for the force on the positively charged ball as.
Here,
Conclusion:
The ball is of the same charge as of the sheet. So, there will be repulsion of ball and ball will deflect away from the sheet.
Substitute
The electric field at the point nearer to the sheet will be same as the electric field at the point away from the sheet as it is independent of the distance of the charged ball from the sheet.
Thus, the ball will deflect same in both the cases.
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Chapter 31 Solutions
Physics for Scientists and Engineers: Foundations and Connections
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