Tag: hooke's law

Questions Related to hooke's law

Assertion (A): Steel is more elastic than rubber.
Reason (R) : Under a given deforming force, steel is deformed less than rubber.


A) Both Assertion and Reason are true and the reason is correct explanation of the assertion
B)Both Assertion and Reason are true, but reason is not correct explanation of the assertion
C) Assertion is true, but the reason is false
D) Assertion is false, but the reason is true

physics hooke's law

  1. A

  2. B

  3. C

  4. D

Show answer
Correct Option: A
Explanation:

More elastic the material, higher the Young's Modulus.
Young's Modulus of Steel = 200 GPa
Young's Modulus of Rubber = 0.01-0.1 GPa
Young's Modulus of Steel is much higher than Rubber, So steel is more elastic than rubber.

Y = FL/Al
Y - Young's Modulus
L - Actual Length
A - Cross Section Area
l - Elongation

l = FL/AY
keeping F,L,A constant 
l is inversely proportional to Y
Hence, Higher the Young's Modulus lesser the deformation (for Different Materials)

Change in the shape of a body caused by the application of a force (stress) is called as :

physics hooke's law

  1. ductility

  2. deformation

  3. hardness

  4. rigidity

Show answer
Correct Option: B
Explanation:

If a force on a body changes the normal positions of the molecules of a body, resulting in a change in the configuration of the body, then the force applied is called deforming force and change in shape of the body is called deformation. 

Change in shape of a body caused by the application of stress is called:

physics hooke's law

  1. rigidity

  2. elasticity

  3. sheer

  4. deformation

Show answer
Correct Option: D
Explanation:

Deformation of a body is the change in shape of a body caused by the application of stress. According to the Hooke's law, the deformation caused in an elastic material is directly proportional to the stress applied to it.

State whether true or false :
While loading the crane with heavy bodies, it is given rest from time to time.

physics hooke's law

  1. True

  2. False

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Correct Option: A

State whether true or false :
The property of an elastic body by virtue of which its behaviour becomes less elastic under the action of repeated alternating deforming force is called elastic fatigue

physics hooke's law

  1. True

  2. False

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Correct Option: A
Explanation:

Elastic fatigue is defined as the temporary loss of elastic properties of a material by applying repeated force on the material. If there is no sufficient time between repeated force application, then a permanent deformation remain there in each time of applying force.

If stress-strain relation for volumetric change is in the form $\cfrac { \Delta V }{ { V } _{ 0 } } =KP$ where $P$ is applied uniform pressure, then $K$ stands for

physics hooke's law

  1. shear modulus

  2. compressibility

  3. Young's modulus

  4. bulk modulus

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Correct Option: B
Explanation:

Bulk modulus $=\cfrac { P }{ \Delta V/V } $
Compressibility$=\cfrac { 1 }{ Bulk\quad modulus } =\cfrac { \Delta V/V }{ P } =K\quad \quad $(Compressibility)

 Time dependent permanent deformation is called

physics hooke's law

  1. Plastic deformation

  2. Elastic deformation

  3. Creep

  4. Anelastic deformation

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Correct Option: C
Explanation:

Creep is a situation in which a component experiences deformation with time as it is put into use. Best example to illustrate this is that electrical cables are taught(tight) when they are installed but after some time they experience sagging due to self weight.

The correct option is option (c)

One end of a uniform wire of length L and of weight W is attached rigidly to a point in the roof and a weight W1 is suspended from its lower end. of S is true area of cross section of the wire, the stress in the wire at a height (3L/4) from its lower end is:

physics hooke's law

  1. [W1 + (W/4)]/S

  2. W1/S

  3. [W1 + (3W/4)]/S

  4. (W1 + W)/S

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Correct Option: C

When a steel rod of length 2m is compressed its length decreases by 0.1m. Find the work done against the compressive stress.$\left( { Y } _{ steel }=2.0\times { 10 }^{ 11 }{ Nm }^{ -2 } \right) $

physics hooke's law

  1. $2.5\times { 10 }^{ 11 } J $

  2. $1.25\times { 10 }^{ 11 } J $

  3. $5.0\times { 10 }^{ 11 } J $

  4. $7.5\times { 10 }^{ 4 } J $

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Correct Option: A

Four wires of the same material are stretched by the same load. The dimension are given below.Which of them will elongate the most?

physics hooke's law

  1. ${\text{Length}}\;100{\text{cm}},{\text{diameter}}\;1{\text{mm}}$

  2. ${\text{Length}}\;200{\text{cm}},{\text{diameter}}\;2{\text{mm}}$

  3. ${\text{Length}}\;300{\text{cm}},{\text{diameter}}\;3{\text{mm}}$

  4. ${\text{Length}}\;400{\text{cm}},{\text{diameter}}\;0.5{\text{mm}}$

Show answer
Correct Option: C