checkpoint_15_amperes_law

Checkpoint Ampere's Law

Amperian Integrals

1)

Two loops are placed near identical current carrying wires as shown in Case 1 and Case 2 below.

For which case is [\oint\limits_{loop} \vec B \cdot d \vec l] greater?

• The integral is the same for both Cases
  • In both cases the current carrying wire is contained within the loop.

2)

Two loops are placed near current carrying wires as shown in Case 1 and Case 2 below.

For which case is [\oint\limits_{loop} \vec B \cdot d \vec l] greater?

• Case 1
  • Case 2 the current carrying wire is outside the loop and therefore zero.

3)

Two loops are placed near current carrying wires as shown in Case 1 and Case 2 below. In both cases the direction of the current in the two wires are opposite to each other.

• Case 2
  • Case 1 the current carrying wires are outside the loop and therefore zero.

Magnetic Field Directions

1)

An infinitely long hollow conducting tube carries current I in the direction shown.

What is the direction of the magnetic field inside the tube?

• the magnetic field is zero
  • because it is contained with in the tube the magnetic field is zero

2)

A current carrying wire is wrapped around cardboard tube as shown below.

In which direction does the magnetic field point inside the tube?

• right
  • I don't konw.