Physics

Katherine Welch

25 July, 16:52

1) the strength of an electromagnet can be increased by

a. replacing the iron core with a steel core

b. using coils of fewer turns on the electromagnet

c. passing a larger current through the electromagnet

d. using thinner wire for the coils

2) the magnetic field lines in the middle of a current-carrying solenoid are

a. spirals

b. circles

c. parallel to the axis of the solenoid

d. perpendicular to the axis of the solenoid

3) two parallel conductors have current flowing through them. in the first instant, the current is flowing in the opposite direction to each other. what are the forces acting on the wires in each case?

a. attraction and repulsion respectively

b. repulsion and attraction respectively

c. attraction for both cases

d. repulsion for both cases