Bourdon tube

Pirani Gauge

micro-manometer

ionisastion gauge

gas law

Boyle′s law

Charle′s law

Pascal′s law

1

1.2

0.8

0.75

decreases linearly with elevation

remains constant

varies in the same way as the density

increases exponentially with elevation

(a) it is the best liquid

(b) the height of barometer will be less

(c) its vapour pressure is so low that it may be neglected

both (b) and (c)