Question

1.         William Gilbert was famous for his scientific works on magnetism, but he also was a physician.  What English royal figure did he become the personal physician for?

2.         What happens to the magnetic properties of magnetic materials when they are heated?

3.         Gadolinium is not magnetic at room temperature.  However, what happens when the metal is submerged in liquid nitrogen?

4.         If you cut a bar magnet in half, do you create “mono-poles”?  In other words, would you have 2 separate pieces, one a “north” and the other a “south”? Explain.

5.         Earth’s magnetic field actually exits at the geographic South Pole.  This means that compass needles on earth point which way?

6.         What does the Solar wind do to Earth’s magnetic field?

7.         Since all magnets are di-poles, what is the total magnetic flux through a closed surface containing a magnet?

8.         Earth’s magnetic field “reverses” on average how often? (every how many years?)

9.         What does an electric charge need to be doing in a magnetic field to experience a “Lorenz Force”?

10.       Earth and Venus are sometimes referred to as sister planets.  However, one fundamental difference is that Venus does not have what?

Answer 1

1.William Gilbert  was Elizabeth I's (queen of England and Ireland)own physician from 1601 until her death in 1603, and James VI and I(James Charles Stuart) renewed his appointment.

2.When heated above 176° Fahrenheit (80° Celsius), magnets will quickly lose their magnetic properties. The magnet will become permanently demagnetized if exposed to these temperatures for a certain length of time or heated at a significantly higher temperature (Curie temperature).

3.

The Curie temperature of gadolinium is 19° C. Cool the gadolinium chunk in liquid nitrogen and suspend it from the magnet. As it warms to room temperature it will drop from the magnet.

With careful spacing of the magnet and cup, it's possible to set the chunk of gadolinium in the cup of LN2 and let it jump to the magnet when it cools. When it warms past its Curie temperature, it will fall back into the cup. The cycle continues until the liquid nitrogen evaporates.

4.Since most bar magnets are actually made up of billions of very small pieces with their magnetic dipoles aligned in the N-S direction of the magnet,then the result would typically be two smaller and somewhat weaker dipole magnets with magnetic field running in the same general direction as the original.

5.

north

A compass needle points north because the north pole of the magnet inside it is attracted to the south pole of Earth's built-in magnet.

6.Solar winds affect earth's magnetic field by the intense clouds of high energy particles that it often contains which are produced by solar storms. When these clouds, called coronal mass ejections, make their way to the Earth in 3-4 days, they collide with the magnetic field of the Earth and cause it to change its shape.

7.Gauss's law for magnetism, which is one of the four Maxwell's equations, states that the total magnetic flux through a closed surface is equal to zero. (A "closed surface" is a surface that completely encloses a volume(s) with no holes.)

8.

once every 200,000 years

Our planet's magnetic field reverses about once every 200,000 years on average. However, the time between reversals is highly variable. The last time Earth's magnetic field flipped was 780,000 years ago, according to the geologic record of Earth's polarity.

9.

The electric charge will have to be "moving"

.A particle of charge q moving with a velocity v in an electric field E and a magnetic field B experiences a force of

{\displaystyle \mathbf {F} =q\mathbf {E} +q\mathbf {v} \times \mathbf {B} }

This is the lorenz force equation.

10.Venus does not have any moons, a distinction it shares only with Mercury among planets in the Solar System. Venus is a terrestrial planet and is sometimes called Earth's "sister planet" because of their similar size, mass, proximity to the Sun, and bulk composition.