If it is 12 noon in New Delhi, what will be the time in London, UK?
- (a)6:30 A.M.
- (b)6:30 P.M.
- (c)5:30 A.M.
- (d)5:30 P.M.
Correct — A, 6:30 A.M. Indian Standard Time is 5 hours 30 minutes ahead of Greenwich Mean Time (London). So when it is 12:00 noon in New Delhi, it is 12:00 minus 5:30 = 6:30 A.M. in London.
- (b)6:30 P.M. — That would put London AHEAD of India; in fact London (GMT) is behind IST by 5.5 hours, so the time there is earlier, in the morning.
- (c)5:30 A.M. — This subtracts 6.5 hours; the IST-GMT difference is 5 hours 30 minutes, giving 6:30 A.M., not 5:30.
- (d)5:30 P.M. — Wrong both in amount and in direction — London is behind India by 5.5 hours, so it is morning there, not evening.
Local time depends on longitude: places east of Greenwich are ahead, places west are behind. Indian Standard Time is based on 82.5 degrees E and is GMT + 5:30. To convert Delhi time to London time, subtract 5 hours 30 minutes (using standard GMT).
Subtract the 5:30 offset from noon: 12:00 - 5:30 = 6:30 A.M. (Note: if the UK is on British Summer Time, clocks there read one hour more, i.e. 7:30 A.M.; the standard GK answer uses GMT.)
- IST = GMT + 5 hours 30 minutes (based on 82.5 degrees E).
- London standard time is GMT (0 degrees, the Prime Meridian).
- 12:00 noon Delhi - 5:30 = 6:30 A.M. London.
- Under British Summer Time, London would be one hour ahead of GMT.
- Getting the direction wrong — London is behind India, so it is earlier there.
- Ignoring the 30-minute part of the 5:30 offset.
Asked as converting between Indian time and another city's time using the standard-time offset.
No directly related past PYQ was found.
- practice — not a real PYQ
Indian Standard Time is based on the longitude
- (a)75.5 degrees E
- (b)82.5 degrees E
- (c)90 degrees E
- (d)0 degrees
Answer(b) 82.5 degrees E.
- practice — not a real PYQ
If it is 12:00 noon at Greenwich, the Indian Standard Time is
- (a)5:30 P.M.
- (b)6:30 P.M.
- (c)6:30 A.M.
- (d)12:00 noon
Answer(a) 5:30 P.M. (GMT + 5:30).