Two charges +q and -q are placed at a distance d apart. Where can a third charge be placed such that the net force on it is zero?
Practice Questions
1 question
Q1
Two charges +q and -q are placed at a distance d apart. Where can a third charge be placed such that the net force on it is zero?
At a distance d/2 from +q
At a distance d/2 from -q
At a distance greater than d from both
At a distance less than d/2 from both
The third charge must be placed between +q and -q, closer to -q to balance the forces.
Questions & Step-by-step Solutions
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Q
Q: Two charges +q and -q are placed at a distance d apart. Where can a third charge be placed such that the net force on it is zero?
Solution: The third charge must be placed between +q and -q, closer to -q to balance the forces.
Steps: 7
Step 1: Understand that we have two charges: +q (positive) and -q (negative) placed at a distance d apart.
Step 2: Recognize that a third charge will experience forces due to both +q and -q.
Step 3: The force exerted by +q on the third charge will be repulsive (pushing it away) if the third charge is positive, and attractive (pulling it in) if the third charge is negative.
Step 4: The force exerted by -q on the third charge will be attractive (pulling it in) if the third charge is positive, and repulsive (pushing it away) if the third charge is negative.
Step 5: To find a position where the net force on the third charge is zero, we need to balance the forces from +q and -q.
Step 6: Place the third charge between +q and -q, but closer to -q. This way, the attractive force from -q will be stronger than the repulsive force from +q, allowing them to balance out.
Step 7: The exact position can be calculated using the formula for electric force, but conceptually, being closer to -q ensures the forces balance.
