Tag: option b: engineering physics

Quizzes (17) Questions (184)

Questions Related to option b: engineering physics

Multiple choice fluid dynamics option b: engineering physics physics

More viscous oil is used in summer than in winter in motors due to

  1. rise in temperature in summer, the viscosity of oil increases.

  2. rise in temperature in summer, the viscosity of oil decreases.

  3. surface tension of oil decreases.

  4. surface tension of oil increases.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Due to rise in temperature viscosity of oil decreases in summers. So more viscous oils are used for better lubricant protection.

Multiple choice fluid dynamics option b: engineering physics physics

With the increasing molecular mass of a liquid, the viscosity .

  1. decreases

  2. increases

  3. no effect

  4. all wrong
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

With the increasing molecular mass of a liquid, the viscosity increases.
The flow of molecules is inversely proportional to its mass. Hence, liquids with high molecular mass possess greater viscosity.

Multiple choice fluid dynamics option b: engineering physics physics

When cooking oil is heated in a frying pan, the oil moves around in the pan more easily when it is hot. The main reason for this is that with rise in temperature, there is a decrease in

  1. density

  2. surface tension

  3. viscosity

  4. angle of contact
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

That is true. The temperature dependence of liquid viscosity is the phenomenon by which liquid viscosity tends to decrease (ore, alternatively, its fluidity tends to increase) as its temperature increase.

Multiple choice viscosity option b: engineering physics properties of matter physics

Viscosity is most closely related to:

  1. density

  2. velocity

  3. friction

  4. energy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Viscosity is the property by virtue of which a liquid offers resistance for the relative motion between liquid molecules. Friction is the force which opposes relative motion between any two objects. So, viscosity is most closely related to friction.

Multiple choice viscosity option b: engineering physics properties of matter physics

Viscosity of the fluids is analogous to:

  1. Random motion of the gas molecules

  2. Friction between the solid surfaces

  3. integral motion

  4. Nonuniform motion of solids
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Viscosity is the property by virtue of which a liquid offers resistance for the relative motion between its layer.
Friction is the force between two solid surfaces which offers resistance for the relative motion between them. 
So, viscosity of the fluids is analogous to friction between the solid surfaces.

Multiple choice viscosity option b: engineering physics properties of matter physics

The main cause of viscosity is:

  1. force of repulsion between molecules.

  2. cohesive forces.

  3. adhesive forces.

  4. both cohesive and adhesive forces.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When the inter-molecular forces of attraction are strong within a liquid, there is a viscosity. Cohesive forces are attractive forces exist between molecules of the same substance. So, cohesive forces are the main cause of viscosity. Adhesive forces are attractive force between unlike molecules.

Multiple choice viscosity option b: engineering physics properties of matter physics

The arrow with a pointed tip can move faster in air than that of with a blunt tip.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The arrow with  a pointed tip can move faster in air than that of with a blunt tip because blunt tip arrow has more area of cross section , so it requires more amount of force to create the same amount of pressure as that by the pointed tip .

so given statement is true  , hence option (A) is correct

Multiple choice viscosity option b: engineering physics properties of matter physics

Viscosity is the property by virtue of which a liquid:

  1. occupies minimum surface area.

  2. offers resistance for the relative motion between its layers.

  3. becomes spherical in shape.

  4. tends to gain its deformed position.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Viscosity is the property by virtue of which a liquid offers resistance for the relative motion between it's layer because it's main cause is cohesive force which acts between like molecules and try to bind them. So, it offers resistance for relative motion between liquid molecules.

Multiple choice viscosity option b: engineering physics properties of matter physics

The cause of viscosity of liquid is:

  1. diffusion.

  2. adhesive force.

  3. gravitational force.

  4. cohesive force.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Due to strong cohesive forces between the molecules, any layer in a moving fluid tries to drag the adjacent layer to move with an equal speed and thus produces the effect of viscosity.