A simple barometer is constructed using a liquid (Q_{1}) of density 16.2(g/cm^{3}). Calculate the least lenth of the tube to be used to measure pressure of 1.5atm. [Density of mercury = 13.6(g/cm^{3}), 1atm = 76.0 cm of Mercury]
-
A.
1358mm -
B.
957mm -
C.
760mm -
D.
638mm
Correct Answer: Option D
Explanation
Let (h_{Q}) and (rho_{Q}) be the least length and the density of (Q_{1})
while (h) and (rho) are the length and density of mercury respectively.
(htimes rho times g = h_{Q} times rho_{Q} times g)
(76cm times 13.6 times 10 = h_{Q} times 16.2 times 10)
(h_{Q} = frac{76times13.6times10}{16.2times10})
(h_{Q} = frac{10336}{162})
(h_{Q} approxeq 63.8cm = 638mm)