# Magnetic field of a coaxial cable#

A portion of a long, cylindrical coaxial cable is shown in the figure. A current $$I$$ flows down the centre conductor, and this current is returned in the outer conductor.

## Part 1#

Determine the magnitude of the magnetic field in the region $$r\\< r_1$$.

In your symbolic expression, you may copy and paste the Greek symbol Î¼0. Use pi to represent Ï€.

## Part 2#

What is the direction of the magnetic field calculated in Part 1?

### Answer Section#

• clockwise

• counterclockwise

• the magnetic field is zero

## Part 3#

Determine the magnitude of the magnetic field in the region $$r_1\\< r\\< r_2$$.

In your symbolic expression, you may copy and paste the Greek symbol Î¼0. Use pi to represent Ï€.

## Part 4#

What is the direction of the magnetic field calculated in Part 3?

### Answer Section#

• clockwise

• counterclockwise

• the magnetic field is zero

## Part 5#

Determine the magnitude of the magnetic field in the region $$r_2\\< r\\< r_3$$.

In your symbolic expression, you may copy and paste the Greek symbol Î¼0. Use pi to represent Ï€.

## Part 6#

What is the direction of the magnetic field calculated in Part 5?

### Answer Section#

• clockwise

• counterclockwise

• the magnetic field is zero

## Part 7#

Determine the magnitude of the magnetic field in the region $$r > r_3$$.

In your symbolic expression, you may copy and paste the Greek symbol Î¼0. Use pi to represent Ï€.

## Part 8#

What is the direction of the magnetic field calculated in Part 7?

### Answer Section#

• clockwise

• counterclockwise

• the magnetic field is zero

## Attribution#

Problem is from the OpenStax University Physics Volume 2 textbook, licensed under the CC-BY 4.0 license.