Electric field strength is defined as the force exerted on a unit positive charge. Which option best matches this definition?

• A. Force per unit negative charge
• B. Force per unit positive charge
• C. Voltage divided by charge
• D. Charge per unit force

Answer: (B)

Electric field strength tells you how much force a small positive test charge would experience per unit of charge at a point. It’s defined by E = F/q, where F is the force on the test charge and q is the charge. If the test charge is unit positive (q = 1), then F directly equals E, so the field strength is the force per unit positive charge.

The other ideas mix in different quantities: voltage divided by charge relates to electric potential, not field strength; charge per unit force is the reciprocal and doesn’t match the definition; and using a negative test charge would give the same magnitude but opposite direction, whereas the standard definition uses a positive test charge.