Two point charges +2 coulomb and +6 coulomb repel each other with a force of 12 N. If a charge of -2 coulombs is given to each of these charges, the force will now be
Correct answer: D. 16 N (attractive)
- A. Zero
- B. 8 N (repulsive)
- C. 8 N (attractive)
- D. 16 N (attractive)
Explanation
After giving each charge a negative charge of -2 coulombs, the net charge of the system becomes +4 coulombs( F= K(q1q2)/r^2 ) since the +2 coulomb and +6 coulomb charges both gain -2 coulombs. Since the charges are now opposite in sign, they will attract each other. Therefore, the force will be 16 N and it will be attractive.Incorrect options: (a) The charges, even after becoming negative, will still interact due to Coulomb's law.(b) The charges now attract each other due to their opposite signs.(c) The force will be attractive, not repulsive.
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Electrostatics describes forces between charges through Coulomb's law, electric fields and field intensity, then uses electric potential to measure energy per unit charge. Capacitors store charge and electrical energy, with capacitance depending on geometry and dielectric material, not simply on the amount of charge present.
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