In a u-tube as shown in the fig. water and oil are<br />in the left side and right side of the tube<br />respectively. The heights from the bottom for water<br />and oil columns are 15 cm and 20 cm<br />respectively. The density of the oil is<br />(take pwater = 1000 kg/m] [NEET-2019 (Odisha)]<br />20 cm<br />15 cm<br />oil<br />water<br />(1) 1333 kg/m3<br />(3) 750 kg/m3<br />(2) 1200 kg/m<br />(4) 1000 kg/m
Answers
Given:
In a u-tube as shown in the fig. water and oil are in the left side and right side of the tube respectively. The heights from the bottom for water and oil columns are 15 cm and 20 cm respectively. (take pwater = 1000 kg/m] [NEET-2019 (Odisha)] (1) 1333 kg/m3 (3) 750 kg/m3 (2) 1200 kg/m (4) 1000 kg/m
To find:
The density of the oil is
Solution:
From given, we have,
The heights from the bottom for water and oil columns are 15 cm and 20 cm respectively. (take pwater = 1000 kg/m]
ho = 15 cm = 150 m
hw = 20 cm = 200 m
The pressure is given by the formula,
P = P₀ + ρgh
where,
P₀ is the initial pressure
ρ is the density of liquid
g is the gravitational constant
h is the height of the liquid
Now consider,
The pressure of the oil is equal to the pressure of the water.
Po = Pw
P₀ + ρogho = P₀ + ρwghw
ρo × ho = ρw × hw
ρo × 200 = 1000 × 150
ρo = (1000 × 150)/200
∴ ρo = 750 kg/m
Option (3) 750 kg/m is correct.