JAMB - Physics (1978 - No. 8)
mercury is a better barometric fluid than water because i. it needs no colouring ii. its density is many times greater than that of water iii. it does not wet glass iv. it has a high vapour pressure v. it has a high boiling point. which of the above statements are true?
i and ii only
i, ii and iii only
iii and iv only
iv and v only
iii, iv and v only
Giải thích
The advantages of use of mercury in a barometer are :
- its density is very high.
- it has low vapor pressure.
- its rate of evaporation is not very high.
- it neither wets nor sticks to glass.
- its surface is shining and opaque.