ANSWER:
(a) 6.3 cm
(b) 0.42 cm
Explanation:
Given:
Density of oil = 0.9 g/cm^3
Density of mercury = 13.6 g/cm^3
Rise in the height of the mercury = 8.33 mm of Hg = 0.833 cm of Hg
(a)
The change in pressure is:

The change in pressure when oil is used is:

Equating the above two equation

The amount of fluid rise is half the difference of level, so the height of rise in the oil

(b) If the manometer uses mercury then
