What does dimension means/how to calculate dimension?

Apossible explanation for a set of facts that can be tested by further investigation is called

The long handle on a rake is a(n) a. lever b. screw c. wedge d. inclined plane

The magnitude of the magnetic field at a certain distance from a long, straight conductor is represented by b. what is the magnitude of the magnetic field at twice the distance from the conductor? a. at twice the distance, the magnitude of the field is 4b.b. at twice the distance, the magnitude of the field is 2b.c. at twice the distance, the magnitude of the field is b/2.d. at twice the distance, the magnitude of the field is b/4.e. at twice the distance, the magnitude of the field remains equal to b.