conceptual questions

1. Can a quantity have units but still be dimensionless?
2. Can a quantity have dimensions but still be unit less?
3. Name two physical quantities which have same dimensions as that of work?
4. Name two physical quantities which have same dimensions as that of pressure?
5. State the number of significant figures in the following :

           (a) 0.0074    (b) 0.23700     (c) 6.230    (d) 89000  (e) 1.0102
     
     6.  Solve the following with due regard to significant figures :
          (a)   .996 x 3.52                     (b) 7.21/2.3

     7.  The diameter of a circle is 2.486 m. Calculate its area with
          due regard to significant figures .
     8.  Bring out the difference between 4.0 and 4.000.
     9.  The length and breadth of a rectangular field are 22.4 cm
           and 15.8 cm respectively and have been measured to an
          accuracy of 0.2 cm. F ind the % error in the measurement
          of its area.