4. The extinction coefficient for different qualities of glasses varies in the range of
A. 5-25 mm-1
B. 5-25 km-1
C. 5-25 m-1
D. 5-25 cm-1
4. The extinction coefficient for different qualities of glasses varies in the range of
A. 5-25 mm-1
B. 5-25 km-1
C. 5-25 m-1
D. 5-25 cm-1