A barometer tube reads 75 cm of Hg. If tube is gradually inclined at an angle of 30° with horizontal, keeping the open end in the mercury container, then find the length of mercury column in the barometer tube

Question

A barometer tube reads 75 cm of Hg. If tube is gradually inclined at an angle of 30° with horizontal, keeping the open end in the mercury container, then find the length of mercury column in the barometer tube (A) 86.7 cm (B) 150 cm (C) 75 cm (D) 92.5 cm

Tardigrade Admin · Accepted Answer

∵ We are not changing the atmospheric pressure, so height of Hg from the surface should not change. (75/x)= cos 60° ⇒ x=150 cm

Q. A barometer tube reads $75 c m$ of $H g$ . If tube is gradually inclined at an angle of $3 0^{\circ}$ with horizontal, keeping the open end in the mercury container, then find the length of mercury column in the barometer tube

86.7 cm

150 cm

75 cm

92.5 cm

$∵$ We are not changing the atmospheric pressure, so height of $H g$ from the surface should not change.
$\frac{75}{x} = cos 6 0^{\circ}$
$\Rightarrow x = 150 c m$

Q. A barometer tube reads 75cm of Hg. If tube is gradually inclined at an angle of 30∘ with horizontal, keeping the open end in the mercury container, then find the length of mercury column in the barometer tube