Answer:
The magnitude of the electric force on sphere A due to sphere B must be F
Step-by-step explanation:
Metal sphere A has a charge = −Q
Metal sphere B has a charge = 2Q
The magnitude of the electric force on sphere B due to sphere A = F
The magnitude of the electric force on sphere A due to sphere B would be same as magnitude of the electric force on sphere B due to sphere A that is F and this force will be attractive in nature due to opposite polarity of charges.