If a proton is moved against the coulomb force of an electric field, then

• A

  work is done by the electric field
• Correct answer
  B

  energy is used from some outside source
• C

  the strength of the field is decreased
• D

  the strength of the field is increased

Solution

Due to field, a proton experiences a force in the direction of field.
To move proton against the field an external agency is required to provide energy to the proton.

Hence, the correct answer is option: 'B'.