Question

An astrologer needs local time of Delhi (whose longitude is about 77/½° E) when the boy was born at 12 noon as per IST. It will be ______.

Options

• 12 hrs 20 min

• 11 hr 30 min

• 12 hr 40 min

• 11 hr 40 min

Answer 1

An astrologer needs local time of Delhi (whose longitude is about 77/½° E) when the boy was born at 12 noon as per IST. It will be 11 hr 40 min.

Explanation:

The Indian Standard Time (IST) is based on the 82½° E longitude. Delhi’s longitude is about 77½° E, which is 5° less than IST longitude. Each degree corresponds to 4 minutes, so local time in Delhi is 20 minutes behind IST. Hence, at 12 noon IST, local time in Delhi is 11 hr 40 min.

Local time = IST – (5° × 4 minutes) = 12:00 – 20 minutes = 11:40 AM.