CBSE
Multiple Choice QuestionsAssertion: Specific gravity of a fluid is a dimensionless quantity
Reason: : It is the ratio of density of fluid to the density of water.
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: Smaller drops of liquid resist deforming forces better than the larger drops.
Reason: Excess pressure inside a drop is directly proportional to its surface area
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 assertion is true but reason is false
Assertion: For Reynold number Re > 2000, the flow of fluid is turbulent.
Reason: Inertial forces are dominant compared to the
viscous forces at such high Reynold numbers.
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: A thin stainless steel needle can lay floating on a still water surface.
Reason: Any object floats when the buoyancy force balances the weight of the object.
If both assertion and reason are true and reason is the correct explanation of the assertion
If both assertion and reason are true but reason is not the correct explanation of the assertion
If assertion is true, but reason is false
Both assertion and reason are false statements
A sphere of mass Mand radius R is falling in a viscous fluid. The terminal velocity attained by the falling object will be proportional to
R2
R
1/R
1/R2
The old age arteries carrying blood in the human body become barrow resulting in an increase in blood pressure. This follows from
Pascal's law
Stoke's law
Bernoulli's principle
Archimedes principle
A given shaped glass tube having uniform cross section is filled with water and is mounted on a rotatable shaft as shown in figure. If the tube is rotated with a constant angular velocity ω when
water levels in both sections A and B go up
water level in section A goes up and that in B comes down
water level in section A comes down and that in B it goes up
water levels remain same in both sections
Bernoulli's equation is a consequence of conservation of
energy
linear momentum
angular momentum
mass
Assertion: Use of ball bearings between two moving parts of a machine is a common practice.
Reason: Ball bearings reduce vibrations and provide good stability.
If both assertion and reason are true and reason is the correct explanation of the assertion
If both assertion and reason are true but reason is not the correct explanation of the assertion
If assertion is true, but reason is false
Both assertion and reason are false statements
A candle of diameter d is floating on a liquid in a cylindrical container of diameter D ( D >> d ) as shown in figure. If it is burning at the rate of 2 cm/hour then the top of the candle will
remain at the same height
fall at the rate of 1 cm/hour
fall at the rate of 2 cm/hour
go up at the rate of 1 cm/hour
