UPSC Prelims 2005 · General Studies
Question 19: Geography
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?
AnswerThe answer is (b).
Statement 1 is wrong: the earth's magnetic axis is tilted by about 11 degrees from the geographic axis; 23½ degrees is the tilt of the rotation axis to its orbit. Statement 2 is accepted: the north magnetic pole was located by James Clark Ross in 1831 on the Boothia Peninsula in northern Canada. Statement 3 is right: the magnetic equator passes near Thumba in Kerala, one reason a rocket station was built there.
- 1. The magnetic axis is inclined about 11°, while 23½° is the axial tilt.
- 2. The north magnetic pole was found on the Boothia Peninsula in northern Canada.
- 3. The magnetic equator passes near Thumba, in Kerala.
How you could have got this
- If you were sure statement 1 is not correct, (a) goes: it includes 1.
What you needed to know: The magnetic axis is inclined about 11°, while 23½° is the axial tilt.
- Then, if you were sure statement 2 is correct, (d) goes: it leaves 2 out.
What you needed to know: The north magnetic pole was found on the Boothia Peninsula in northern Canada.
- Then, if you were sure statement 3 is correct, (c) goes: it leaves 3 out.
What you needed to know: The magnetic equator passes near Thumba, in Kerala.
Only (b) is left. This one needs every statement.
This follows an unofficial answer: UPSC has not published its key for this year, and if that answer is wrong, so is this path.
Which options go is worked out from UPSC’s key and the options, not by a model.
Why each option is right or wrong
- (a) Statement 1 is false: the magnetic axis is tilted about 11°, not 23½°.
- (b) Correct: statements 2 and 3.
- (c) Misses statement 3: the magnetic equator passes near Thumba.
- (d) Misses statement 2, which the key accepts.
Worth knowing: The north magnetic pole has drifted since: by 2005 it lay in the Arctic Ocean north of Canada, away from Boothia Peninsula, so statement 2 is a dated fact.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2005, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.