Tag: substances in the surroundings - their states and properties

Questions Related to substances in the surroundings - their states and properties

Which of the following statements is incorrect?

chemistry substances in the surroundings - their states and properties elastic behaviour of solids elastic and plastic substances properties of substances

  1. When a material is under tensile stress, the restoring forces are caused by interatomic attraction while under compressional stress, the restoring force is due to interatomic repulsion

  2. The stretching of a coil is determined by its shear modulus

  3. Rubber is more elastic than steel

  4. Shearing stress plays an important role in the buckling of shafts

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Correct Option: C
Explanation:

More elastic means, the value of an elastic constant is more and. Steel have move elastic constant in compare to Rubber, So Steel is more elastic than rubber.
All other statements are correct.

Out of the following whose elasticity is independent of temperature

chemistry substances in the surroundings - their states and properties elastic behaviour of solids elastic and plastic substances properties of substances

  1. steel

  2. copper

  3. Invar steel

  4. glass

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Correct Option: C
Explanation:

For most of the materials, elasticity decreases with temperature. One exception is invar steel.

Fill in the blank.
In a technical sense a substance with a ________ elasticity is one that requires a ______  force to produce a distortion-for example, a steel sphere. 

chemistry substances in the surroundings - their states and properties elastic behaviour of solids elastic and plastic substances properties of substances

  1. high, small

  2. high, large

  3. low, large

  4. low , small

Show answer
Correct Option: B
Explanation:

According to Hooke's law, within elastic limit,

    $E=\dfrac{stress}{strain}$$=\dfrac{deforming\ force}{(area\times strain)}$ 
It means higher the elasticity, larger will be the required deforming force.
Hence, in a technical sense a substance with a high elasticity is one that requires a high force to produce a distortion.

As compared to concrete, steel has compressive strength:

chemistry substances in the surroundings - their states and properties elastic behaviour of solids elastic and plastic substances properties of substances

  1. $25$ times less

  2. equal

  3. $25$ times more

  4. $5$ times more

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Correct Option: C
Explanation:

Compressive strength is the capacity of a material or structure to withstand loads tending to reduce size, as opposed to tensile strength, which withstands loads tending to elongate.

Compressive strength is one of the most important engineering property of Concrete which designers are concerned of. However the compressive strength of steel is around 25 time more than that of concrete.

Elasticity is defined as the ability of a body to 

chemistry substances in the surroundings - their states and properties elastic behaviour of solids elastic and plastic substances properties of substances

  1. Resist linear motion in a hard surface

  2. Resist rolling motion in a hard surface

  3. Resist a distorting influence and to return to its original size and shape when that influence or force is removed.

  4. Resist electric current in a magnetic field

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Correct Option: C
Explanation:

Elasticity is defined as the ability of a body to  resist a distorting influence and to return to its original size and shape when that influence or force is removed.

Substances that elongate considerably and undergo plastic deformation before they break are known as

chemistry substances in the surroundings - their states and properties elastic behaviour of solids elastic and plastic substances properties of substances

  1. brittle substances

  2. breakable substances

  3. ductile substances

  4. all of these

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Correct Option: C
Explanation:

Substances that elongate considerably and undergo plastic deformation before they break are known as ductile substances

Substances that break just after elastic limit is reached are known as 

chemistry substances in the surroundings - their states and properties elastic behaviour of solids elastic and plastic substances properties of substances

  1. brittle substances

  2. breakable substances

  3. ductile substances

  4. elastic substances

Show answer
Correct Option: A
Explanation:

Substances that break just after elastic limit is reached are known as brittle substances

An elastic metal rod will change its length when it

chemistry substances in the surroundings - their states and properties elastic behaviour of solids elastic and plastic substances properties of substances

  1. falls vertically under its weight

  2. is pulled along its lengthy by a force acting at one end

  3. both

  4. none

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Correct Option: B

Which one of the following substance possesses the highest elasticity?

chemistry substances in the surroundings - their states and properties elastic behaviour of solids elastic and plastic substances properties of substances

  1. rubber

  2. glass

  3. steel

  4. copper

Show answer
Correct Option: C
Explanation:

Modulus of elasticity gives the idea of elasticity. For above materials, values of E are:
Glass: $50-90 GPa$
Rubber:$ 0.01-0.1 GPa$
Steel:$ 200 GPa$
Copper: $117 GPa$

Pick up the correct statement:

chemistry substances in the surroundings - their states and properties elastic behaviour of solids elastic and plastic substances properties of substances

  1. Cubic crystals exhibit isotropic nature with respect to therma expansion

  2. Anisotropic solids expand in one direction and contract in perpendicular direction

  3. Many of the crystals are anisotropic solids

  4. Rock salt crystal exhibits isotropic nature with respect to thermal expansion

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Correct Option: C