A barometer tube reads 76 cm of mercury. If the tube is gradually inclined at an angle of 30° with vertical, keeping the open end immersed in the mercury reservoir, the length of the mercury column will be

Question

A barometer tube reads 76 cm of mercury. If the tube is gradually inclined at an angle of 30° with vertical, keeping the open end immersed in the mercury reservoir, the length of the mercury column will be (A) 70 cm (B) 89 cm (C) 88 cm (D) 100 cm

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/795e5d2769e8ab8e8fa955b8fc65f080-.png" /> cos 30°=( h /ℓ) ℓ=( h / cos 30°)=(76/(√3)2)=(152/√3) ℓ=87.75 cm

Q. A barometer tube reads $76 c m$ of mercury. If the tube is gradually inclined at an angle of $3 0^{\circ}$ with vertical, keeping the open end immersed in the mercury reservoir, the length of the mercury column will be

$70 c m$

$89 c m$

$88 c m$

$100 c m$

$cos 3 0^{\circ} = \frac{h}{ℓ}$
$ℓ = \frac{h}{c o s 3 0 ^{\circ}} = \frac{76}{\frac{3}{2}} = \frac{152}{3}$
$ℓ = 87.75 c m$

Q. A barometer tube reads 76cm of mercury. If the tube is gradually inclined at an angle of 30∘ with vertical, keeping the open end immersed in the mercury reservoir, the length of the mercury column will be

70cm

89cm

88cm

100cm