CBSE
Multiple Choice QuestionsViscous force exerted by the liquid flowing between two plates in a streamline flow depends upon the
velocity gradient in the direction perpendicular to the plates
area of plate
co-efficient of viscosity of the liquid
all of these
Pressure head in Bernoulli's equation is
ρ g
Pρg
Assertion: A needle placed carefully on the surface of water may float, whereas the ball of the same material will always sink.
Reason: The buoyancy of an object depends both on the materials and shape of the object.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: Turbulence is always dissipative.
Reason: High reynold number promotes turbulence.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
A solid sphere of volume V and density p floats at the interface of two immiscible liquids of densities and p, respectively. If ρ1 < ρ < ρ2, then the ratio of volume of the parts of the sphere in upper and lower liquid is
Assertion: When height of a tube is less than liquid rise in the capillary tube, the liquid does not overflow.
Reason: Product of radius of meniscus and height of liquid in the capillary tube always remain constant.
If both assertion and reason are true and reason is the correct explanation of assertion.
f both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: Surface energy of an oil drop is same whether placed on glass or water surface.
Reason: Surface energy is dependent only on the properties of oil.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
A cylindrical tank is filled with water to level of 3 m. A hole is opened at height of 52.5 cm from bottom. The ratio of the area of the hole to that of cross-sectional area of the cylinder is 0.1. The square of the speed with which water is coming out from the orifice is (Take g = 10 m s-2)
50 m2 s-2
40 m2 s-2
51.5 m2 s-2
50.5 m2 s-2
A spherical body of diameter D is falling in viscous medium. Its terminal velocity is proportional to
Vt ∝ D1/2
Vt ∝ D3/2
Vt ∝ D2
Vt ∝ D5/2
Two spherical soap bubbles of radii a and b in vacuum coaleasce under isothermal conditions. The resulting bubbles has a radius given by
a+ b
