The bar used for defining the standard metre at the International office of weights and measures at Sevres near Paris, is composed of

The bar used for defining the standard metre at the International offi

1.	The bar used for defining the standard metre at the International office of weights and measures at Sevres near Paris, is composed of
A.	50% platinum and 50% iridium
B.	60% platinum and 40% iridium
C.	70% platinum and 30% iridium
D.	80% platinum and 20% iridium
Answer» E.