At noon.
It is noon when both the clock's hands are on twelve and the sun is overhead.
overhead
The sun is never overhead at 42 degrees north.
The sun is at its peak at noon, when it is directly overhead.
Hawaii.
Noon, because the sun is directly overhead.
Not quite directly overhead, but close. Thats why it is called high noon.
Because the clocks across the whole of India are based on when the sun is overhead in Delhi. You are West of Delhi and so when the sun is overhead in Jaipur, it has already passed its overhead / noon position in Delhi.
Nowhere on earth.
I think that the sun is only ever directly overhead the equator at noon on any day of the year.
If the Sun is overhead, it is "noon". There are complications due to exactly how we define noon and time zones, but that's probably a good enough answer. If you want to be more exact it is noon according to the "local apparent solar time". The sun can only ever be overhead if you live within about 23.4 degrees of the equator (namely between the Tropics of Cancer and Capricorn). Even there, the sun will only be overhead on one or two days of the year at any location.