Physics-
General
Easy
Question
A ball of radius r and density 
falls freely under gravity through a distance h before entering water. Velocity of ball does not change even on entering water. If viscosity of water is 
, the value of h is given by
The correct answer is:
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Physics-
Two capillary tubes of equal length and inner radii 2r and 4r respectively are added in series and a liquid flows through it. If the pressure difference between the ends of the whole system is 8.5 cm of mercury, find the pressure difference between the two ends of the first capillary tube.
Two capillary tubes of equal length and inner radii 2r and 4r respectively are added in series and a liquid flows through it. If the pressure difference between the ends of the whole system is 8.5 cm of mercury, find the pressure difference between the two ends of the first capillary tube.
Physics-General
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A metal ball of radius 'r' and density 'd' travels with a terminal velocity 'v' in a liquid of density d/4. The terminal velocity of another ball of radius '2r' and density ' 3 d ' in the same liquid is
A metal ball of radius 'r' and density 'd' travels with a terminal velocity 'v' in a liquid of density d/4. The terminal velocity of another ball of radius '2r' and density ' 3 d ' in the same liquid is
Physics-General
Physics-
In a surface tension experiment, the lower end of a capillary tube of radius r is placed vertically in water. It is observed that with rise in water heat is evolved. When liquid rises to a height of 2 cm, the angle of contact is zero. If the tube is depressed more now so that the top of the capillary is only 1 cm above the liquid, the angle of contact changes. If the same experiment is repeated in an artificial satellite, still water rises. If water rises to height h, the heat evolved is? ( d is the density of water)
In a surface tension experiment, the lower end of a capillary tube of radius r is placed vertically in water. It is observed that with rise in water heat is evolved. When liquid rises to a height of 2 cm, the angle of contact is zero. If the tube is depressed more now so that the top of the capillary is only 1 cm above the liquid, the angle of contact changes. If the same experiment is repeated in an artificial satellite, still water rises. If water rises to height h, the heat evolved is? ( d is the density of water)
Physics-General
Physics-
Consider a small surface area of 
at the top of a mercury drop of radius 4 mm. If atmospheric pressure 
p and surface tension of mercury 0.465 N/m. Neglect the effect of gravity The force exerted on this area by the mercury surface in contact with it
Consider a small surface area of at the top of a mercury drop of radius 4 mm. If atmospheric pressure p and surface tension of mercury 0.465 N/m. Neglect the effect of gravity The force exerted on this area by the mercury surface in contact with it
Physics-General
Physics-
The capillaries shown in figure have inner radii 0.5 mm,1.0 mm and 1.5 mm respectively. The liquid in the beaker is water. Find the heights of water level in the capillaries. The surface tension of water is 
.
The capillaries shown in figure have inner radii 0.5 mm,1.0 mm and 1.5 mm respectively. The liquid in the beaker is water. Find the heights of water level in the capillaries. The surface tension of water is .
Physics-General
Physics-
A liquid is contained in a vertical tube of semicircular cross-section. The contact angle is zero. The force of surface tension on the curved part and on the flat part are in ratio
A liquid is contained in a vertical tube of semicircular cross-section. The contact angle is zero. The force of surface tension on the curved part and on the flat part are in ratio
Physics-General
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The inter molecular forces of attraction within a liquid gives rise to a phenomenon known as surface tension. On the basis of molecular theory the molecules of the liquid molecules tends to attain almost a spherical shape. However for large drops the shape is not perfectly spherical. The free energy contained in a liquid surface per unit area is surface tension. If a capillary tube is immersed or kept in contact with a liquid surface, the liquid rises or falls in capillary tube when compared to the level of liquid in out side. The rise or fall depends on the cohesive and adhesive forces. A container of width 
is filled with a liquid. A thin wire of mass per unit length 
is gently placed on the middle of the surface as shown in fig. As a result the liquid surface is depressed by a distance y. The surface tension of liquid is given by
The inter molecular forces of attraction within a liquid gives rise to a phenomenon known as surface tension. On the basis of molecular theory the molecules of the liquid molecules tends to attain almost a spherical shape. However for large drops the shape is not perfectly spherical. The free energy contained in a liquid surface per unit area is surface tension. If a capillary tube is immersed or kept in contact with a liquid surface, the liquid rises or falls in capillary tube when compared to the level of liquid in out side. The rise or fall depends on the cohesive and adhesive forces. A container of width is filled with a liquid. A thin wire of mass per unit length is gently placed on the middle of the surface as shown in fig. As a result the liquid surface is depressed by a distance y. The surface tension of liquid is given by
Physics-General
Physics-
A light open rigid wire frame floats on the surface of water as shown in fig. What force will act on the frame due to surface, immediately after some soap solution is dropped inside it 
and 
are the surface tensions of water and soap solutions respectively 
.
A light open rigid wire frame floats on the surface of water as shown in fig. What force will act on the frame due to surface, immediately after some soap solution is dropped inside it and are the surface tensions of water and soap solutions respectively .
Physics-General
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A soap bubble has radius R and thickness d(<<R) as shown. It collapses into a spherical drop. The ratio of excess pressure in the drop to the excess pressure inside the bubble is
A soap bubble has radius R and thickness d(<<R) as shown. It collapses into a spherical drop. The ratio of excess pressure in the drop to the excess pressure inside the bubble is
Physics-General
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A liquid is filled in a spherical container of radius R till a height h. At this positions the liquid surface at the edges is also horizontal. The contact angle is
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Physics-General
Physics-
A uniform rod of density , and length 'l' is having square cross-section of side 'a'. It is placed in a liquid of equal density vertically along length in a tank having sufficient height of liquid. The surface tension of liquid is 'T' and angle of contact is 120° Then :
A uniform rod of density , and length 'l' is having square cross-section of side 'a'. It is placed in a liquid of equal density vertically along length in a tank having sufficient height of liquid. The surface tension of liquid is 'T' and angle of contact is 120° Then :
Physics-General
Chemistry-
The number of atoms in 100 g of an fcc crystal with density d = 10 g 1 cm3 and cell edge as 200 pm is equal to:
The number of atoms in 100 g of an fcc crystal with density d = 10 g 1 cm3 and cell edge as 200 pm is equal to:
Chemistry-General
Chemistry-
Which of the following is incorrect
Which of the following is incorrect
Chemistry-General
Physics-
If a number of small droplets of water each of radius r coalesce to form a single drop of radius R, then the rise of temperature is : (J= mechanical equivalent of heat, d= density of water, T= surface tension of water)
If a number of small droplets of water each of radius r coalesce to form a single drop of radius R, then the rise of temperature is : (J= mechanical equivalent of heat, d= density of water, T= surface tension of water)
Physics-General
Physics-
The pressure inside two soap bubbles is 1.01 and 1.02 atmosphere respectively. The ratio of their volumes is (atmospheric pressure 
)
The pressure inside two soap bubbles is 1.01 and 1.02 atmosphere respectively. The ratio of their volumes is (atmospheric pressure )
Physics-General
