Properties of Bulk Matter

Stress, strain, elasticity, Hooke’s law and other notions linked to fluids like as Pascal’s law, viscosity, surface energy and so on are all examples of bulk matter properties. Internal restorative force exerted on a deformed body per unit area is known as stress. The strain, on the other hand, is the ratio of the change in body shape to the initial body shape. Within the elastic limits, stress is directly proportional to strain, according to Hooke’s law. Below you will get to know about the MCQs related to the topic- properties of bulk matter.

1. Which of the following is defined by hooke’s law:

1. Modulus of elasticity

2. Stress

3. Strain

4. Elastic limit

 Answer: a) modulus of elasticity, because the proportionality unit is the NM2. As a result, modulus of elasticity can be defined as the ratio of stress to strain in a material. The slope of the stress-strain curve in the elastic deformation area is thus defined as the modulus of elasticity of a material. As a result, Hooke’s law is used to describe modulus of elasticity.

2. What is liquid stiffness modulus?

1. There is no modulus in rigidity.

2. Infinite

3. Zero

4. Non-zero constant

Answer: c) zero, because for water, the Modulus of Rigidity or Shear Modulus is 0.

Water will begin to flow as a result of any imposed force and the strain will become extremely big.

3. If the temperature increases, what happens to the modulus of elasticity?

1. Increases

2. Decreases

3. Remains constant

4. Becomes zero

Answer: b) decreases, because Increased temperature in the metal substance can cause atoms in the crystal structure to vibrate more, resulting in increased atomic distance and decreased atomic force. The material’s modulus of elasticity may be reduced as a result of this.

4. Which is responsible for a typical body’s shape changing?

1. Volume stress

2. Shearing strain

3. Metallic strain

4. Longitudinal strain

Answer: b) shearing strain, because Shear stress, on the other hand, does not produce shape change; it is shear load or shear traction that does. There’s a distinction to be made between traction and stress. The cause is traction and the impact is stress.When it comes to the question, shear is, by definition, a volume-preserving deformation. Normal and shear stress can be defined for a body in a generalised state of stress along any random plane. Normal stress and shear stress are two different types of stress that help us understand how a material reacts to applied stresses. Shear produces form change and normal stress causes pure dilatation (extension or contraction).

1. When an iron needle is slowly lowered onto the water’s surface,it floats.

2. The density of the material used in the needle is lesser than that of the water.

3. Surface tension is responsible.

4. Water is displaced which is equal to the needle.

5. It is dependent on the shape.

Answer: b) surface tension is responsible, because Surface Tension is a term that describes a liquid’s tendency to diminish its surface area. The cohesive force between water molecules near the surface and those inside the bulk pulls them in, giving them a higher potential energy than those inside.

EXPLANATION: The surface tension in a liquid is caused by cohesive interactions between the molecules. On each side of the molecules in the liquid’s bulk are neighbouring molecules. Molecules are tugging in all directions equally, resulting in a net force of zero.

6. A force is exerted at a 30 degree angle to a cube that is fixed on a table surface. What kind of transformation will the cube go through?

1. The cube will just topple.

2. A change in shape.

3. Change in size.

4. Change in both shape and size.

Answer: d) change in both shape and size, because When the force is applied, the cube will move parallel to the surface while also compressing. As a result, the size of the object will alter.Because the force direction is not symmetric, the compression will not be symmetric. As a result, its shape will shift. When a force is applied to an item, it can alter shape and size by compressing, stretching or bending. When a spring is pulled from both ends, for example, the size and shape of the spring is altered due to the force applied.

7. The lengths of the two wires A and B, which are made of the same material, are 1:2. The ratio of their diameters is 2:1. If the wires are stretched by the same force, what will be the length ratio?

1. 2:1

2. 8:1

3. 1:4

4. 1:8

Answer: d) 1:8, because  by using young modulus/hooke’s law .

1. Which of these materials is unaffected by an applied elastic force?

2. Copper

3. Quartz

4. Steel

5. Rubber

Answer: b) quartz, because Elastic behaviour of solids: Elasticity is the ability of solid materials to revert to their original shape and size after being deformed by external forces. The molecules that make up solids are kept together by intermolecular forces. When a solid is subjected to an external force, the molecules are moved, resulting in deformation. Intermolecular forces drive the molecules back to their original position once the force is no longer acting. This is the process by which materials get their original shape and size. Stress is created by the forces acting on the materials. When continuous stress is placed beyond a material’s elastic limit, the material begins to deform. The elastic after effect is the time it takes for an object to regain its original shape and size after it has been deformed within the elastic limit. If the material has a high elastic after effect, it is less elastic in nature and if it has a low elastic after effect, it is more elastic in nature.