Magnetism (determining the magnetic field)

AI Thread Summary
To determine the magnetic field around a current-carrying wire, the right-hand rule is essential. For a long straight wire aligned north-south with current flowing north, the magnetic field directly above the wire points east. When assessing the field to the left of the wire, it is necessary to visualize the coordinate system, where "left" corresponds to the west direction. The magnetic force on a proton traveling north above the wire can also be identified using the right-hand rule, which helps clarify the directional relationships. Understanding these concepts will aid in solving related problems effectively.
jojo14
Messages
5
Reaction score
0
I just need help on how to solve these problems. I am so confused with the directions that i just don't get it...

1) A long straight wire is aligned north-south and carries current in the northerly direction. What is the direction of the magnetic field created directly abvove the wire?
Answer: East

2) What is the direction of the magnetic field created immediately to the left of the wire?
a. Downward
b. south
c. east
d. west
e. upward
f. north

3) If a proton is traveling north directly above the wire, what is the direction of the magnetic force on the proton due to the wire?
a. upward
b. south
c. downward
d. north
e. west
f. east

I just need an explanation on why, and how to do this? I know it's the right hand rule, but i dont' get the questions that are asking the placement, for example number 2 says to the left of the wire? what does that mean? and like number 1 says above the wire? what does that mean?
how do i go about this?

any help is greatly appreciated. thanks!
 
Physics news on Phys.org
Just draw the wire and set up a coordinate system. You know the wire goes N and S so you can label that. From those you can label E and W as well. Then "above the wire" is just above the plane of the wire or above sheet of paper.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top