EASY
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A manometer reads the pressure of a gas in an enclosure as shown in the figure. What is the absolute and gauge pressure of the gas in cm of mercury ? (take atmospheric pressure = 76 cm of mercury)
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Important Questions on Thrust and Pressure

MEDIUM
A submarine experiences a pressure of 5.05×106 Pa at a depth of d1 in a sea. When it goes further to a depth of  d2 , it experiences a pressure of  8.08×106 Pa . Then d2-d1 is approximately (density of water =103 kg/m3 and acceleration due to gravity  =10 ms-2 ):
MEDIUM
A body of density ρ and volume V is lifted through height h in a liquid of density σ<ρ. The increase in potential energy of the body is
MEDIUM
There is a circular tube in a vertical plane. Two liquids which do not mix and of densities d1 and d2 are filled in the tube. Each liquid subtends 90o angle at centre. Radius joining their interface makes an angle α with vertical. Ratio d1d2  is:
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HARD

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Two liquids of densities ρ1 and ρ2ρ2=2ρ1 are filled up behind a square wall of side 10 m as shown in figure. Each liquid has a height of 5 m. The ratio of the forces due to these liquids exerted on upper part MN to that at the lower part NO is (Assume that the liquids are not mixing):

EASY
Two non-mixing liquids of densities ρ and nρn>1 are put in a container. The height of each liquid is h. A solid cylinder of length L and density d is put in this container. The cylinder floats with its axis vertical and length pLp<1 in the denser liquid. The density d is equal to:
HARD
A wooden block floating in a bucket of water has 45 of its volume submerged. When certain amount of an oil is poured into the bucket, it is found that the block is just under the oil surface with half of its volume under water and half in oil. The density of oil relative to that of water is:
MEDIUM
The approximate depth of an ocean is 2700 m . The compressibility of water is 45.4×10-11 Pa-1 and density of water is 103  kg/m 3. What fractional compression of water will be obtained at the bottom of the ocean ?
HARD

A cylindrical vessel containing a liquid is rotated about its axis so that the liquid rises at its sides as shown in the figure. The radius of vessel is 5 cm and the angular speed of rotation is ω rad s-1. The difference in the height, h in cm of liquid at the Centre of vessel and at the sides of the vessel will be :

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MEDIUM
A long cylindrical vessel is half filled with a liquid. When the vessel is rotated about its own vertical axis, the liquid rises up near the wall. If the radius of vessel is 5 cm and its rotational speed is 2 rotations per second, then the difference in the heights between the center and the sides, in cm, will be:
MEDIUM
A uniform cylinder of length L and mass M having cross-sectional area A is suspended, with its length vertical, from a fixed point by a massless spring, such that it is half submerged in a liquid of density σ at equilibrium position. The extension x 0 of the spring when it is in equilibrium is :
 
HARD
Consider a solid sphere of radius R and mass density ρr=ρ01-r2R2,0<rR. The minimum density of a liquid in which it will float is:
HARD

An open-ended U-tube of uniform cross-sectional area contains water (density 103 kg m-3 ). Initially the water level stands at 0.29 m from the bottom in each arm. Kerosene oil (a water-immiscible liquid) of density 800 kg m-3 is added to the left arm until its length is 0.1 m, as shown in the schematic figure below. The ratio h1h2 of the heights of the liquid in the two arms is

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EASY
An aluminium sphere is dipped into water. Which of the following is true?
MEDIUM
A cubical block of side 0.5 m floats on water with 30% of its volume under water. What is the maximum weight that can be put on the block without fully submerging it under water?
[Take, density of water  =103 kg/m3 ]
EASY
The density of kerosene is 800kg m-3. Its relative density is
MEDIUM
An ice-berg of density 900 kg m-3 is floating in water of density 1000 kg m-3. The percentage of volume of ice-berg outside the water is 
MEDIUM

A barometer is constructed using a liquid (density =760 kg m-3). What would be the height of the liquid column, when a mercury barometer reads 76 cm?

(density of mercury =13600 kg m-3)

HARD

A cylindrical block of wood (density = 650 kg m-3), of base area 30 cm2 and height 54 cm, floats in a liquid of density 900 kg m-3. The block is depressed slightly and then released. The time period of the resulting oscillations of the block would be equal to that of a simple pendulum of length (nearly) :

HARD
Consider a vessel filled with a liquid upto height H. The bottom of the vessel lies in the X-Y plane passing through the origin. The density of the liquid varies with Z-axis as ρz=ρ02-zH2. If P1 and P2 are the pressures at the bottom surface and top surface of the liquid, the magnitude of P1-P2 is :
MEDIUM
A U tube with both ends open to the atmosphere is partially filled with water. Oil, which is immiscible with water, is poured into one side until it stands at a distance of 10 mm above the water level on the other side. Meanwhile, the water rises by 65 mm from its original level (see diagram). The density of the oil is ____ρw=1000 kg m-3
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