The Total solution for NCERT class 6-12
Answer - 21 : -
Answer - 22 : - Distinguishing between Number and AutoNumber data
Number
AutoNumber
It holds numeric values which are used for calculations.
It allows to store numbers that are automatically generated for each record.
The field length of this data type is 1,2, 4, 8 or 16 bytes.
The field length of this data type is 4 bytes.
It does not support field property New values.
It supports the field property New values.
e.g. in a table Employee, Salary is a Number type field.
e.g. in a table Bank, the AccountNo is a AutoNumber field as, for every new customer, this field will automatically increase and will provide a new number.