Physics Test 10

Based on the fact that compasses allow us to know direction, which of the following does this indicate?

• The Earth is a permanent magnet.

• The Earth is an electromagnet.

• The Earth was formed from gas and dust.

• The Earth is over 5 billion years old.

A magnet has to be touching another material to exert a force.

• True

• False

Which of the following does the illustration depict?

• an electric field

• a magnetic field

• a carbon atom

• a water molecule

A(n) ________________________ is an exerted area around the magnetic force. It is obtained by moving electric charges. The direction of the magnetic field is indicated by lines.

• magnetic field

• electric field

• gravity well

• distortion of space-time

Earth's geographic north pole and the Earth's magnetic north pole are in the same place.

• True

• False

Which of the following do scientists think generate the Earth’s magnetic field?

• electrical currents flowing in the liquid outer core deep inside the Earth

• the friction between the Earth's surface and its atmosphere

• the interaction of the solar winds with Earth's atmosphere

• the Moon's pull of gravity on the Earth's oceans

Which of the following would occur if the Earth did not have its magnetic field? CHOOSE ALL THAT APPLY!

• The Sun's solar wind would strip away our atmosphere.

• The Sun's radiation would make life on Earth improbable or impossible.

• Plants on Earth would grow twice as fast but only live half as long.

• Aircraft would be able to fly much faster.

The Earth’s magnetic field reverses itself every 250,000 years or so. The north magnetic pole becomes the south pole, and vice versa.

• True

• False

Which of the following produces a magnetic field?

• moving electrical charges

• the interaction between hydrogen and helium atoms

• the interaction between iron and aluminum atoms

• atoms with more protons than neutrons

Choose the best description of what's shown in the diagram.

• magnetic field lines

• electrical field lines

• electron orbitals

• vectors of circular motion