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Following bearings are observed while traversing with a compass.
Line Fore Bearing Back Bearing AB 126°45' 308°00' BC 49°15' 227°30' CD 340°30' 161°45' DE 258°30' 78°30' EA 212°30' 31°45'
After applying the correction due to local attraction, the corrected fore bearing of line BC will be
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- 48°15'
- 50°15'
- 49°45'
- 48°45'
- 48°15'
Correct Option: D
The difference between back bearing and fore bearing of line DE = 258°30' – 78° 30' = 180°
∴ Station D and E are free from local attraction
Fore bearing of line EA = 212° 30'
Correct back bearing of line EA = 216° 30' – 180° = 36° 30'
∴ Error at A = 31° 45' – 36° 30' = – 4° 45'
Hence correction at A = + 4° 45'
∴ Correct fore bearing of line AB = 126°45' + 4°45'= 131° 30'
Correct back bearing of AB = 131° 30 + 180° = 311° 30'
∴ Error at B = – 3° 30'
Correction at B = + 3° 30'
Hence correct bearing of BC = 45° 15' + 3° 30' = 48° 45'
