Since electric field is defined as E = E, this means that the magnitude of the electric field at a location in space is equal 90 to the magnitude of the electric force acting on a test charge qo divided by the magnitude of that test charge. In equation form: E = 1901 Consider the situation shown, in which a positive charge +Q is fixed in space. +Q Our goal is to use the definition of the electric field to find an expression for the magnitude of the electric field caused by charge +Q at point A, which is at a distance d from it. B. What is the direction of the electric field caused by charge + Q at point A? A d A. Place a test charge qo at point A. To make things simple, make the test charge positive. Use Coulomb's law to write the magnitude of the electric force that exerted by charge +Q on charge qo, then use the definition written above to write an expression for the magnitude of the electric field caused by charge +Q at point A. C. How would your answers to A and B change if the charge was negative, that is -Q? Important: Make sure your answer for the magnitude ends up being positive.