Final Exam

If a large bar magnet is cut in half, each half will

• contain a North pole only

• either contain a North pole only or contain a South pole only, depending
  on the pole of the original bar magnet

• contain a South pole only

• 
  contain no poles

• contain both a North and South pole

Most locations on Earth have a magnetic declination because

• Earth's magnetic South pole is located nearby, but not exactly at true
  North

• Earth rotates on its North-South axis

• Earth's magnetic South pole is located at true South

• Earth's magnetic North pole is located at true North
  e.
  Earth's magnetic North pole is located nearby, but not exactly at true

• North

A compass needle always points towards North because

• Earth's magnetic North pole is located nearby, but not exactly at true
  North

• Earth's magnetic South pole is located nearby, but not exactly at true
  North

• Earth's magnetic South pole is located at true South

• 
  Earth's magnetic North pole is located at true North

• Earth rotates on its North-South axis

A current in a wire produces a magnetic field around it. What happens to a stationary charge placed in
this magnetic field?

• it feels no force

• either it feels a force towards the wire or it feels a force away from the
  wire, depending on the direction of the current in the wire

• it feels a force towards the wire
  

• it feels a force away from the wire
  

• it produces its own magnetic field

  
  

Two electromagnets, A and B, have a different number of turns and a different current in them.
Electromagnet A has more turns than B (in the same amount of space), and electromagnet A has more
current through it than B. How does the strength of their magnetic fields compare?

• we need to know the current to determine an answer
  

• the magnetic field strength of A is greater than that of B
  

• the magnetic field strength of A is equal to that of B
  

• we need to know the number of turns to determine an answer
  

• the magnetic field strength of A is less than that of B
  

Which statement is true regarding the relationship between electricity and magnetism?

• current in a wire produces a magnetic field
  

• a changing electric field produces a magnetic field
  

• moving electric charges produce a magnetic field
  

• a changing magnetic field produces an electric field
  

• all of the choices
  

Why does a transformer not work with DC?

• the magnetic fields produced in DC are too small
  

• the magnetic fields produced in DC are constant
  

• the voltages in DC are too small
  

• the voltages in DC are too large
  

• the magnetic fields produced in DC are too large
  

If an alternating current (AC) is input to a stereo speaker, the speaker will oscillate with the same
frequency as the AC source. What will happen if DC is input to the speaker?

• the speaker will function louder than normal
  

• the speaker will function as a microphone
  

• the speaker will function normally
  

• the speaker will function quieter than normal
  

• the speaker will not oscillate
  

The correct sequence of electromagnetic waves, in order of increasing wavelength is

• gamma rays, ultraviolet, visible, infrared, radio waves

• visible, ultraviolet, infrared, radio waves, gamma rays

• radio waves, infrared, visible, ultraviolet, gamma rays
  

• radio waves, ultraviolet, visible, infrared, gamma rays
  

• infrared, visible, ultraviolet, radio waves, gamma rays
  

What is the significant difference between x-rays and microwaves?

• x-rays always have a lower amplitude than microwaves
  

• x-rays always have a constant electric field, while
  microwaves have an oscillating electric field.

• x-rays always have a higher amplitude than microwaves
  

• x-rays always have a higher frequency than microwaves
  

• x-rays always have a lower frequency than microwaves