Posts Tagged ‘physics’

Continuity of Magnetic Field Lines

I was taught in school that magnetic lines can not cross each other without breaking. Also i was taught that magnetic field lines are unidirectional traveling out of the north end of the magnetic field and connecting to the south magnetic pole. My question is, In the event of the lines being broken, would the broken or open north magnetic lines coming out of the north pole of the magnetic field( traveling at the speed of 186,000 miles per second, the speed of light) be able to connect with any other south magnetic poles they encounter even a second or more away.thank you, Ron G.

Why there is no magnetic field around a disconnected copper wire

Moving electrons produce magnetic field right? Electrons on earth are moving at an average of 27.83m/s due to earths rotation plus 30m/s due to earths revolution and may be more due to sun’s revolution and our galaxy’s revolution.
since there is no absolute motion, how can we tell if electrons are moving?
If the electrons are moving, anyway, why is there no magnetic field around a disconnected copper wire?

Asked  N.Srichakradhar Reddy

Right hand rule is a physics principle applied to electric current passing through a straight wire, resulting in a magnetic field. The thumb points in the direction of the conventional current (from positive to negative), and the fingers in the direction of the magnetic field. (Photo credit: Wikipedia)

Majoring in physics?

Hi there, I have finally (at 22 and third year in college) decided what I want to major in–physics! I love it, so so so much! I especially want to be an astrophysicist. However, after hearing from a bunch of people, my professor included, astrophysicists don’t get paid much, and a lot of people want to do it. This really bummed me out, because that’s my true passion. However, I don’t want to major in it, spend 8 years in school, and then not find a job, or find a lower paying job. I have a daughter, and I don’t have room to take chances too much. I need to get stable for the both of us. I genuinely want a six figure salary, and I would love to be able to do research, my life goal is to make a major contribution to physics. However, I just don’t know what I can do with a physics degree that will get me paid a decent amount, while at the same time doing what I love. Any advice or suggestions?

Questions posted via PhysicsFans.com chat

• In nuclear physics during beta- decay a  proton is converted to neutron,positron and a neutrino. How it’s possible for a proton to decay into more massive neutron. And it’s said that the decay is possible only when it’s inside the nucleus. so whether any other factors is involved in this decay?
• We study in magnetism that Earth’s magnetism has 3 components namely declination Inclination,Horizontal component of Earth’s magnetic field. What is the cause of declination? Why it changes from place to place?