what is the only planet that was considered the giant magnet?

Answer 1

Neptune because of the amount of Iron on the planet

Answer 2

The internal magnetic field of the Earth results from the interplay of some very definite features: the existence of a liquid, electrically conducting core, the rotation of the Earth and the presence of energy sources in the core, which cause the fluid to circulate. It thus came as a surprise that other planets of the solar system, very different from Earth, also had their own magnetic fields

http://www.phy6.org/earthmag/mill_8.htm

Answer 3

Amy J gave a very good answer. Based on your use of "was" and "only", it would have to be Jupiter. However, ALL the gas giants fulfill the criteria of giant magnet, with Earth & Mars relegated to "small magnet"

Answer 4

I believe it is Jupiter.

Read this:

Magnetosphere
Jupiter has a very large and powerful magnetosphere. In fact, if one could see Jupiter's magnetic field from Earth, it would appear five times as large as the full moon in the sky despite being so much farther away. The magnetic field is generated by eddy currents in Jupiter's metallic hydrogen core. This magnetic field collects a large flux of particle radiation in Jupiter's radiation belts, as well as producing a dramatic gas torus and flux tube associated with Io. Jupiter's magnetosphere is the largest planetary structure in the solar system. [8]

The Pioneer probes confirmed that Jupiter's enormous magnetic field is 10 times stronger than Earth's and contains 20,000 times as much energy. The sensitive instruments aboard found that the Jovian magnetic field's "north" magnetic pole is at the planet’s geographic south pole, with the axis of the magnetic field tilted 11 degrees from the Jovian rotation axis and offset from the center of Jupiter in a manner similar to the axis of the Earth's field. The Pioneers measured the bow shock of the Jovian magnetosphere to the width of 26 million kilometres (16 million miles), with the magnetic tail extending beyond Saturn’s orbit.

The data showed that the magnetic field fluctuates rapidly in size on the sunward side of Jupiter because of pressure variations in the solar wind, an effect studied in further detail by the two Voyager spacecraft. It was also discovered that streams of high-energy atomic particles are ejected from the Jovian magnetosphere and travel as far as the orbit of the Earth. Energetic protons were found and measured in the Jovian radiation belt and electric currents were detected flowing between Jupiter and some of its moons, particularly Io.

Answer 5

Actually it is Jupiter

Answer 6

Jupiter has the largest planetary magnetic field known, so that is probably the answer.

Answer 7

Roseanne Barr

Answer 8

Uranus

Answer 9

the ex planet pluto

Answer 10

Earth because of its nickel and iron core.