UPSC Prelims 2005 Q19: Geography – Astronomy & Earth - Sun System
Consider the following statements :
1. The axis of the earth’s magnetic field is inclined at 23 ½° to the geographic axis of the earth.
2. The earth’s magnetic pole in the northern hemisphere is located on a peninsula in northern
Canada.
3. Earth’s magnetic equator passes through Thumba in South India.
Which of the statements given above is/are correct?
- (a) 1, 2 and 3
- (b) 2 and 3
- (c) 2 only
- (d) 3 only
Answer: (b) 2 and 3
Explanation
Earth's magnetic field
| Statement | Verdict |
|---|---|
| 1. Magnetic axis inclined at 23.5 degrees to geographic axis | False: about 11.5 degrees (23.5 is axial tilt) |
| 2. North magnetic pole is on a peninsula in northern Canada | True — in the Canadian Arctic, near Boothia Peninsula |
| 3. Magnetic equator passes through Thumba | True — Thumba, near Thiruvananthapuram |
Statements 2 and 3 are correct. The 23.5 degree figure is the tilt of the Earth's rotational axis.
Answer: (b) 2 and 3.
Why each option is right or wrong
- (a) Incorrect. Statement 1 mixes magnetic tilt with axial tilt.
- (b) CORRECT. Statements 2 and 3 are correct.
- (c) Incorrect. Statement 3 is also correct.
- (d) Incorrect. Statement 2 is also correct.
Key point
Magnetic tilt about 11.5 degrees; Thumba lies on the magnetic equator, hence its rocket launching station.
Remember
The magnetic equator passes through Thumba.
Common mistakes
- Confusing the axial tilt (23.5) with magnetic inclination (11.5).
- Putting the north magnetic pole in Greenland.
- Forgetting Thumba's role as an equatorial station.
Exam tip
Thumba: magnetic equator, India's first rocket launch site (1963).
Sources
- NCERT Class XII Physics — Magnetism and Matter
- Indian Space Research Organisation — Thumba Equatorial Rocket Launching Station (TERLS), Thiruvananthapuram