Tag: option b: engineering physics

Questions Related to option b: engineering physics

Hot syrup flows faster because:

fluid dynamics option b: engineering physics physics

  1. Surface tension increases when temperature is increased.

  2. Viscosity decreases when temperature is increased.

  3. Viscosity increases when temperature is increased.

  4. Surface tension decreases when temperature is increased.

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Correct Option: B
Explanation:

Hot syrup is liquid at higher temperature. We know that as temperature increases viscosity decreases for liquids. So, hot syrup flows faster as viscosity decreases.

Assertion : Water flows faster than honey.
Reason: The coefficient of viscosity of water is less than honey.

fluid dynamics option b: engineering physics physics

  1. Both assertion and reason are true and reason is correct explanation of assertion.

  2. Both assertion and reason are true but reason is not the correct explanation of assertion.

  3. Assertion is true but reason is false.

  4. Both assertion and reason are false.

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Correct Option: A
Explanation:

Velocity is inversely proportional to coefficient of viscosity, $\eta$ of water is less than that of honey.
Hence, water flows faster than honey.

With increase in temperature, the viscosity of:

fluid dynamics option b: engineering physics physics

  1. gases decreases and liquid increases

  2. gases increases and liquid decreases

  3. both gases and liquid increases

  4. both gases and liquid decreases

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Correct Option: B
Explanation:

The viscosity of liquid is inversely proporional to the square of the temperature, therefore as we increase the temperature, the viscosity of liquids will decrease.


Similarly, the viscosity of gases is linearly proportional to the temperature. hence as the temperature increases, the viscosity will increase

A spaceship entering the earth's atmosphere is likely to catch fire. This is due to:

fluid dynamics option b: engineering physics physics

  1. The surface tension of air

  2. Air Friction

  3. The high temperature of upper atmosphere

  4. The greater portion of oxygen in the atmosphere at greater height.

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Correct Option: B
Explanation:

As the body enters Earth's atmosphere, it falls at very high speeds. This high speeds cause a lot of friction with the air, causing the parts to catch fire.
Option B.

When an object is dropped into a fluid, the extent of splash, due to buoyant force of fluid, depends on:

fluid dynamics option b: engineering physics physics

  1. sliding friction

  2. rolling friction

  3. fluid friction

  4. static friction

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Correct Option: C
Explanation:

The splash, due to buoyant force of a fluid depends on fluid friction.

If a toy boat in a tan sinks, the level of water will.

fluid dynamics option b: engineering physics physics

  1. Fluctuate

  2. Decrease

  3. Increase

  4. Remain the same

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Correct Option: C

Vehicles are streamlined to reduce 

fluid dynamics option b: engineering physics physics

  1. Static friction

  2. Kinetic friction

  3. Fluid friction

  4. Slidingfriction

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Correct Option: C
Explanation:

Fishes have streamlined shape. So, to reduce the fluid friction, the vehicles are made streamlined.

A good lubricant should be highly

fluid dynamics option b: engineering physics physics

  1. viscous and velocity

  2. non-viscous volatile

  3. viscous and non-volatile

  4. transparent

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Correct Option: A
Explanation:

A good lubricant generally possesses the following characteristics: A high boiling point and low freezing point (in order to stay liquid within a wide range of temperatures) A high viscosity index. Thermal stability.

Two spheres $A$ and $B$ fall through the same viscous fluid. $A$ and $B$ have the same density and $B$ has the larger radius.
Then,

fluid dynamics option b: engineering physics physics

  1. A has the larger terminal velocity

  2. A and B have the same terminal velocity

  3. B has the larger terminal velocity

  4. Insufficient information is given to reach a conclusion.

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Correct Option: C
Explanation:

Two spheres $A$ and $B$ fall through the same viscous fluid $A$ and $B$ have  the same density and $B$ has the larger radius the $B$ has the larger terminal velocity.

$\therefore $ Option $C$ is correct.

Ball pen and fountain pen depends respectively on principle of:-

fluid dynamics option b: engineering physics physics

  1. Surface tension and viscosity

  2. Surface tension and gravity

  3. Gravitation and Surface tension

  4. Surface tension and Surface tension

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Correct Option: A