Consider the arrangement of two fixed point charges, equal in magnitude, shown i
ID: 1661116 • Letter: C
Question
Consider the arrangement of two fixed point charges, equal in magnitude, shown in the figure. Which of the following statements are correct for the initial motion of a third charge if it is released from rest in the vicinity of the two charges shown? True or false?
1. A negative charge at point b will accelerate down.
2. A negative charge at point e will accelerate up.
3. A negative charge at point c will accelerate toward the lower-right.
4. A negative charge at point a will accelerate toward the lower-right.
5. A positive charge at point d will accelerate up.
Explanation / Answer
1] True. A negative charge at b will be repelled downwards due to the upper negative charge and it will be attracted downwards due to the lower positive charge.
2] True. A negative charge at e will be repelled weakly by upper negative charge but it will be attracted strongly upwards due to the nearer positive charge.
3] False. A negative charge at c will be repelled diagonally downwards to the right by the upper negative charge and it will be attracted diagonally downwards to the left by the lower positive charge and so its resultant will be downwards (if the charges are equal).
4] False. A negative charge at a will be repelled diagonally downwards to the left by the upper negative charge and it will be attracted diagonally downwards to the right by the lower positive charge and so its resultant will be downwards (if the charges are equal).
5] False. A positive charge at d will be repelled weakly by the lower positive charge and it will be attracted strongly by upper negative charge and so its resultant will be downwards.