Question

1.Which of the following statements about the direction of a magnetic force is always true? (Note: More than one answer choice may be correct

	a.	The direction of the magnetic force on a moving charged particle is perpendicular to the direction of the external magnetic field.
	b.	The direction of the magnetic force on a moving charged particle is parallel to the direction of the charged particle's velocity.
	c.	The direction of the magnetic force on a moving charged particle is parallel to the direction of the external magnetic field.
	d.	The direction of the magnetic force on a moving charged particle is perpendicualr to the direction of the charged particle's velocity

2. Permanent magnets attract ALL metals through ferromagnetism.

True

False

3. When a standard bar magnet (made of billions of atoms and molecules) is cut exactly in half, each piece always becomes a smaller bar magnet that has its own magnetic North and South poles.

True

False

4. The magnitude of the magnetic field a certain distance away from a long, straight conductor (e.g. a wire) is B. What is the magnitude of the magnetic field at half the distance away from the conductor?

	a.	4B
	b.	2B
	c.	B
	d.	B/2
	e.	B/4

Answer 1

1) Magnetic force on a moving charge is perpendicular to both the magnetic field and the velocity. So the correct options are:

(a) The direction of the magnetic force on a moving charged particle is perpendicular to the direction of the external magnetic field.

(b) The direction of the magnetic force on a moving charged particle is perpendicular to the direction of the charged particle's velocity

2)

(a) True.

3)

(a) True

Magnetic monopoles do not exist.

4)

(b) 2B

B is inversely proportional to distance r.