What is the value of the horizontal component of the earth's magnetic field at the poles?

Explanation

To determine the value of the horizontal component of the Earth's magnetic field at the poles, we can follow these steps:

### Step 1: Understand the Earth's Magnetic Field
The Earth's magnetic field can be visualized as lines of magnetic force that emerge from the North Pole and enter the South Pole. At the poles, these lines are oriented vertically.

### Step 2: Analyze the Orientation of the Magnetic Field
At the North Pole, the magnetic field lines emerge vertically upwards, and at the South Pole, they enter vertically downwards. This means that at both poles, the magnetic field has no horizontal component.

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