Question

part a - multiple choice/true or false - please answer all q

1. which of the following statements regarding magnetism are true?

a) magnetic field lines have a definite start and end point.
b) a solenoid with an iron core is a weaker electromagnet than just
c) monopoles have not yet been proven to exist.
d) dropping a magnet and breaking it into pieces will destroy any
magnet may have.

1. a vertical wire carries electric current into the page. what is the di

magnetic field at point p?

n

w ⊗ e

.p
s

a) west

Explanation:

Question 1:

• Option a: Magnetic field lines are closed loops, so they have no definite start/end. False.
• Option b: An iron core in a solenoid strengthens the electromagnet (iron is a ferromagnetic material that concentrates the magnetic field), so a solenoid with an iron core is stronger. The statement says it's weaker, so False (assuming the "just" in option b refers to a solenoid without an iron core).
• Option c: Magnetic monopoles (isolated north or south poles) have not been experimentally proven to exist. True.
• Option d: When a magnet is broken, each piece becomes a smaller magnet with its own north and south poles. The magnetic properties (having a magnetic field) are not destroyed. So the statement is False.

Using the right - hand rule for a current - carrying wire (thumb in current direction - into the page), the magnetic field direction at point P (below the wire) is west.

Answer:

c) Monopoles have not yet been proven to exist.

Question 2:

To determine the direction of the magnetic field around a current - carrying wire, we use the right - hand rule for a current - carrying wire:

• Grasp the wire with your right hand, with your thumb pointing in the direction of the current.
• The direction in which your fingers curl around the wire is the direction of the magnetic field.

In this problem, the current is going into the page. So, we point our right - hand thumb into the page.

• At point P (which is below the wire), when we curl our fingers around the wire (with the thumb into the page), the direction of the magnetic field at point P is West.