High concentration of red blood cells increases the viscosity of blood from:
Choose the correct answer.
The source indicates the viscosity of blood is several times that of water; the intended answer is option C.
The velocity of falling raindrops attains limited value because:
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As speed increases, viscous drag increases until it balances the effective weight.
If a raindrop with a mass of 0.05 g falls with constant velocity, the retarding force of atmospheric friction is (neglect density of air):
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At constant velocity, net force is zero, so atmospheric drag balances the weight. 0.05 g × 980 cm/s² = 49 dynes.
The working of carburetor or car uses:
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A carburetor uses pressure differences associated with fluid flow.
Ball pen functions on the principle of:
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The source associates the working of a ball pen with viscosity.
In the equation of continuity, ρAv =
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The mass flow rate is ρAv.
The velocity of flow of a liquid through an orifice at the bottom of a tank depends on the:
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Torricelli’s theorem gives v = √(2gh), where h is the liquid height above the orifice.
A two-meter-high tank is filled with water. If a hole appears at its middle then the speed of efflux is:
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The liquid head above the middle hole is 1 m; use v = √(2gh).
When a fluid passes through the constricted part of a pipe, its:
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By continuity velocity increases in the narrow section; Bernoulli’s equation then gives lower pressure.
The velocity of raindrop attains constant value because of:
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Viscous drag increases with speed until the net force becomes zero.
Bernoulli’s equation is applicable in the case of:
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The standard school-level form assumes steady, streamlined flow of an incompressible, non-viscous fluid.
An incompressible fluid flows steadily through a cylindrical pipe which has a radius 2r at a point A and radius r at B farther along the flow direction. If the velocity at point A is v, the velocity at point B will be:
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By continuity, A₁v₁ = A₂v₂. The area at A is four times the area at B.
An ideal liquid flows through a horizontal tube of variable diameter. The pressure is lowest where the:
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For horizontal flow, Bernoulli’s equation gives lower pressure where velocity is higher.
According to Stokes’ law drag force depends on:
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F = 6πηrv, so drag depends on viscosity, radius and velocity.
A cylinder is filled with a non-viscous liquid of density d to a height h₀ and a hole is made at a height h₁ from the bottom of the cylinder. The velocity of the liquid issuing out of the hole is:
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Torricelli’s theorem uses the height of liquid above the orifice: h₀ − h₁.
The rate of leak from a hole in a tank is:
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Pressure and efflux speed are greater for a hole with a larger liquid head above it.
Two light balls are suspended. When a stream of air passes through the space between them, the distance between the balls will:
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Faster air between the balls produces lower pressure, pushing the balls together.
When the terminal velocity is reached, the acceleration of a body moving through a viscous medium is:
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At terminal velocity the speed is constant, so acceleration is zero.
An atmosphere:
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An atmosphere (atm) is a unit of pressure.
Raindrops are spherical because of:
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Surface tension tends to minimize the surface area of a liquid drop, producing a spherical shape.
