What is the magnitude and direction of an electric field that exerts a 2.00 * 10^-5 n upward force on a −1.5 μc charge?

The relation between electric field intensity, electric force and charge is given as follow,

Where,

F = Force

q = Charge

The direction of force on a charge placed in an electric field is same as the direction of electric field if the charge has positive polarity and opposite if charge has negative polarity.

Replacing we have that

As direction of force is upward and polarity of charge is negative, hence the direction of field will be opposite to that of force. Therefore direction of field is downward.

so easy. just google the electromagnetic waves and it’ll pop up.