I am having trouble figuring out this question:
Part 1: A long staight wire carries a current due East. This wire creates, at point #1, a magnetic field that is derected at 40 deg below due South. From point #1, the wire is located:
50 deg below due North
50 deg below due South
40 deg above due North
40 deg above due South
50 deg above due West
50 deg above due East
40 deg below due West
40 deg below due East
directly above
directly below
none of these choices
Part 2: Refer to the previous problem. An electron at point #1 is instantaneously traveling due North. Due only to the wire, the electron at #1 instantaneously accelerates:
East
West
North
South
directly up
directly down
50 deg N or West
50 deg S of East
none of the above
Part 1: To determine the direction where the wire is located, we need to consider the information given about the magnetic field it creates at point #1. The magnetic field is directed at 40 degrees below due South. From this information, we can determine the direction of the wire.
40 degrees below due South corresponds to the direction that is 40 degrees clockwise from the due South direction. Therefore, the wire is located 40 degrees below due South.
So the answer is: 40 deg below due South.
Part 2: The instantaneous acceleration of the electron at point #1 due to the wire can be determined by applying the right-hand rule. When the current-carrying wire is pointing south, and the electron at point #1 is instantaneously traveling due North, their relative motion creates a magnetic force on the electron.
According to the right-hand rule, if you point your right thumb in the direction of the current (due East) and your fingers in the direction of the electron velocity (due North), then the resulting magnetic force will point in the direction perpendicular to both the current and the velocity. In this case, the force will point towards the West.
Therefore, the electron at point #1 instantaneously accelerates towards the West.
So the answer is: West.
To solve this question, we need to use a couple of principles of magnetism and the right-hand rule.
For Part 1, we are given that the wire creates a magnetic field at point #1 that is directed 40 degrees below due South. We need to determine the location of the wire relative to point #1.
To do this, we can recall the right-hand rule for a straight current-carrying wire. When you point your thumb in the direction of the current, your fingers curl in the direction of the magnetic field. In this case, the magnetic field is directed below due South.
If we extend our fingers below due South, the curl of our fingers will be towards the wire. This means that the wire will be located above our hand, which represents point #1.
Looking at the given choices, the wire is located directly above point #1. So the answer is "directly above".
For Part 2, we need to determine the instantaneous acceleration of an electron at point #1 due to the wire's magnetic field.
Recall the right-hand rule for the force on a moving charged particle in a magnetic field. If you point your thumb in the direction of the velocity of the charged particle and your fingers in the direction of the magnetic field, then the force on the charged particle is perpendicular to both.
In this case, the electron is instantaneously traveling due North, and the magnetic field at point #1 is directed 40 degrees below due South.
If we point our thumb due North and our fingers below due South, the palm of our hand will be facing downward. This means that the force on the electron will be directed downwards.
Looking at the given choices, the instantaneous acceleration of the electron is "directly down". So the answer is "directly down".
To summarize:
Part 1: The wire is located "directly above" point #1.
Part 2: The electron at point #1 instantaneously accelerates "directly down" due to the wire's magnetic field.