Question

Lab Scenario:

You don't have a current meter in your underequipped lab.

So you make one out of a compass.

The wire you want to measure the current in is aligned with the North South line.

You place your compass directly under the wire at a distance of 10cm from the wire.

With no current flowing, the compass needle points due north.

When you turn on the current, the compass needle points 5 degrees west of north.

You now have enough information to find the current in the wire, and whether it's flowing north or south!

Hint: the strength of the horizontal component of Earths magnetic field in Orlando is 25 micro Teslas and points due North.

1. what is the value of the current in the wire? Answer in Amps.
2. What direction is the current flowing?
3. What is the value of the magnetic field due to the current at the location of the compass? Answer in micro Teslas.
4. What direction is the magnetic field pointing at the location of the compass?
5. What would the deflection of the compass needle be if the compass is lowered to 20 cm below the wire.

Answer 1