Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice physics hooke's law

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

  1. shear modulus

  2. compressibility

  3. Young's modulus

  4. bulk modulus
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

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

Multiple choice physics hooke's law

 Time dependent permanent deformation is called

  1. Plastic deformation

  2. Elastic deformation

  3. Creep

  4. Anelastic deformation
Reveal answer Fill a bubble to check yourself
C Correct answer
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)

Multiple choice physics hooke's law

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:

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

  2. W1/S

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

  4. (W1 + W)/S
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The stress at any point is the force acting on the cross-section divided by the area S. At a height 3L/4 from the bottom, the weight supported is the suspended weight W1 plus the weight of the wire segment below that point, which is (3/4)W. Thus, the total force is W1 + (3/4)W, and stress is (W1 + 3W/4)/S.

Multiple choice physics hooke's law

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) $

  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 $
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice physics hooke's law

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

  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. ${\text{Length}}\;400{\text{cm}},{\text{diameter}}\;0.5{\text{mm}}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Elongation delta L is given by (FL) / (A Y). Since the load F, material Y, and length are related, we can maximize elongation by having a large length and a very small cross-sectional area (diameter). Option D provides the longest length and the smallest diameter, resulting in maximum elongation.

Multiple choice physics hooke's law

Four identical hollow cylindrical columns of steel support a big structure of mass $50,000$ kg. The inner and outer radii of each column are $30$cm and $40$cm respectively.Assuming the load distribution to be uniform. Calculate the compressional strains of each column, the young's modulus of steel is $2 \times {10^{11}}Pa$

  1. $2.78 \times {10^{ - 6}}$
  2. $3.78 \times {10^{ - 6}}$
  3. $2.78 \times {10^{ - 4}}$
  4. $3.78 \times {10^{ - 4}}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Compressional strain is stress divided by Young's modulus. Total force is mass times gravity, shared equally among four columns. Calculating the cross-sectional area using inner and outer radii yields the stress, which when divided by Young's modulus gives the strain of 2.78 x 10^-6.

Multiple choice physics hooke's law

An elastic metal rod will change its length when it

  1. falls vertically under its weight

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

  3. rotates about an axis at one end

  4. slides on a rough surface
Reveal answer Fill a bubble to check yourself
B,C Correct answer
Explanation

An elastic metal rod will change its length when it is pulled along its length by a force acting at one end or rotates about an axis at one end. Since, deforming force exceeds the elastic limit.

Multiple choice physics hooke's law

Length of a wire is increased by 1 mm on the application of a given load. If same load is applied to another wire of same material but of length and radius twice that of the first then increase in its length will be 

  1. $2 mm$
  2. $\dfrac{1}{2} mm$
  3. $4 mm$
  4. $\dfrac{1}{4} mm$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$\dfrac{{stress}}{{strain}} = y$

$strain = \dfrac{{stress}}{y}$
$\dfrac{{\Delta l}}{l} = \dfrac{f}{{\Delta y}}$
$\Delta l = \dfrac{f}{y} \cdot \dfrac{l}{A}$
$\Delta l' = \dfrac{f}{y} \cdot \dfrac{{2l}}{{\pi \left( {2{r^2}} \right)}}$
$\Delta l' = \dfrac{f}{y} \cdot \dfrac{{2l}}{{4A}}$
$\Delta l' = \dfrac{{\Delta l}}{2} = \dfrac{1}{2}mm$
Hence,
option $(B)$ is correct answer.

Multiple choice physics hooke's law

The maximum stress developed in the rod is equal to $(N/m^{2})$.

  1. $5\times 10^{7}$
  2. $5\times 10^{8}$
  3. $4\times 10^{7}$
  4. $4\times 10^{8}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice physics hooke's law

Which of the following is/are true about deformation of a material?

  1. Deformation capacity of the plastic hinge and resilience of the connections are essential for good plastic behavior

  2. Deformation capacity equations considering yield stress and gradient of moment

  3. Different materials have different deformation capacity

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In well-designed steel frame structures, inelastic deformation under severe seismic loading is confirmed in beam plastic hinges located near the beam-to-column connections. Thus, deformation capacity of the plastic hinge and resilience of the connections are essential for good plastic behavior and expected energy dissipation in steel frame structures. This essential plastic behaviour at the hinge is strongly influenced by the difference of material properties. Generally, the material properties are specified in terms of yield stress and/or ultimate strength. However, the characteristics of the materials are not defined by only these properties. Thus, the characteristics of various materials aren’t reflected in present building codes, particularly on deformation capacity classification.