Question

A U-tube having a horizontal arm of length $20 \, cm$ , has a uniform cross-sectional area $1 \, cm^{2}$ . It is filled with water of volume $60 \, cc$ . The volume of a liquid of density $4 \, g \, cc^{- 1}$ required to be poured in one arm of the U-tube so that no water is left in the horizontal arm of the tube is (take $g=9.8 \, m \, s^{- 2}$ )

• A. $60 \, cc$
• B. $45cc$
• C. $50cc$
• D. $35cc$

Answer 1

Answer: (D)

$\text{h} \text{ρ} \text{g} = 6 0 \times 1 \times \text{g}$
$\text{h} = 1 5 \text{cm}$
$\left(\text{g} = 980 \left(\text{cm sec}\right)^{- 2}\right)$
Volume $= \left(1 5 + 2 0\right) \times 1 = 3 5 \text{cc}$