What is upper circuit and lower circuit?

[Master]

Hey Friends,

Can anybody give me an idea about what is upper circuit and lower circuit in share market? And what is the limit for this?

Thanks,
>Take

The exchange has fixed circuit filters for the Sensex. If the index drops 10% before 1 PM then trading would be halted for one hour. If 10% drop is between 1-2:30 PM then trading to be halted for half an hour. If 10% drop after 2:30 PM then no halt in trading.

If in case index drops by 15% before 1 pm then trading to be halted for 2 hours. If 15% drop between 1-2 PM then trading to be halted for one hour. If 15% drop after 2 PM then trading to be halted for rest of the day.

In the case of 20% drop in the index then trading to be halted for the rest of the day.