my physics question

1. What is Candela?
2. What is the unit of solid angle?
3. Quantity of matter contained in a body is---------
4. Fermi is equal to------------
5. How many basis units are there in Si system?
6. What is Watt?
7. Give one example for dimensionless quantity.
8. -------- has the same dimensional formula
9. which error can be minimised by identifying the source of error?
10. what is the rounded value of 2.078?

1.