Answer:
Negative charges: B and C
Explanation:
The electric field produced by a single point charge has a radial shape and decreases as we move away from the charge, following an inverse square law.
The direction of the field depends on the sign of the charge. In particular:
- If the charge is positive, the electric field is outward - so the field lines point away from the charge
- If the charge is negative, the electric field is inward - so the field lines point toward the charge
Therefore in this image, in order to identify the negative charges, we have to identify the charges that have field lines pointing towards them.
So we have:
- In the figure on top, field lines go away from charge A and towards charge B --> so charge B is negative
- In the figure on bottom, field lines go away from charge D and towards charge C --> so charge C is negative
Therefore, the negative charges are B and C.
