MCQ Detailed View

A magnetometer is a scientific instrument designed to measure the strength and direction of magnetic fields. It is commonly used in physics, geophysics, navigation, and space science to detect variations in the Earth’s magnetic field.

Earth behaves like a giant magnet due to the movement of molten iron and other materials in its outer core. This creates a geomagnetic field that protects our planet from harmful solar radiation and plays a vital role in navigation. However, this field is not constant; it varies in strength and direction depending on geographic location, geological structures, and solar activity. A magnetometer is used to record these changes accurately.

Key Functions of a Magnetometer:

1️⃣ Measuring Earth’s Magnetic Field:
It detects both the magnitude (strength) and direction of magnetic forces around a specific point on the planet.

2️⃣ Magnetic Surveys:
Used in geological surveys to locate mineral deposits or study the Earth's crust by identifying magnetic anomalies.

3️⃣ Navigation and Aerospace Applications:
Spacecraft and aircraft use magnetometers for orientation and to study space weather phenomena such as solar winds and magnetic storms.

4️⃣ Archaeological Use:
Helps detect buried structures or artifacts by identifying disturbances in the natural magnetic field.

Why Other Options Are Incorrect:

• 
  

  Air pressure on ships is measured using barometers, not magnetometers.

  
  


• 
  

  Electromagnetic force in space devices is measured by electrometers or ammeters, not magnetometers.

  
  


• 
  

  Oceanic current changes are measured with current meters or flow sensors.

  
  

Thus, a magnetometer is specifically used to detect and measure variations in the Earth's magnetic field, making option 3 the correct choice.

✅ Correct Answer: Changes in the Earth’s Magnetic Field.