# Civil Engineering - UPSC Civil Service Exam Questions - Discussion

Discussion Forum : UPSC Civil Service Exam Questions - Section 10 (Q.No. 2)
2.
In an old map, line PQ was drawn to a magnetic bearing of 6°32', the magnetic declination at that time being 1° East. The present magnetic declination is 9°42' East. The magnetic bearing to which the line is set at present is
357° 50'
356° 50'
3° 10'
2° 10'
Explanation:
No answer description is available. Let's discuss.
Discussion:
6 comments Page 1 of 1.

John said:   2 years ago
The correct answer is 2° 10'.

VEENA A MOHAN said:   4 years ago
@Karan.

First, we have found out true bearing.

TB is MB plus East declination always. (ie if E is given add if W is given subtract). Then you got TB. From that TB only u r gonna find the MB.

So, MB +Eis TB.
Here you need MB.ie TB -E.

Karan Panjabi said:   5 years ago
The declination in both the case is EAST, so how it is possible to first add for magnetic declination and then subtract for the same EAST direction?

Faisal said:   5 years ago
Yes, true bearing is equal to magnetic bearing (+-) declination - is used when west and + used when east so correct answer is A.

Roy said:   7 years ago
According to me, TB=MB (+/-) declination . So TB=6.32+1=7.32.

Now, mb=7.32-9.42= -2°10' I think as it is -2°10 so it is,
(360°-2°10)=357°50'..

Correct me, if I am wrong.

Lara said:   7 years ago