5. Pressure and Deformation in Solids

Explain the term atmospheric pressure along with its units. How is atmospheric pressure measured with a liquid barometer? Explain its construction and applications.

Atmospheric pressure is the pressure exerted by the weight of the Earth’s atmosphere on a given surface. It is caused by the molecules in the air colliding with surfaces, and it acts in all directions. The atmosphere exerts pressure on everything on Earth’s surface, including people, objects, and even the Earth’s own surface. Unit of … Read more

Define and explain pressure. What is the effect of area on pressure acting on a surface?

Pressure is the force applied per unit area on a surface. It quantifies how concentrated a force is on a particular area. The formula for pressure is: Pressure=Force/Area​ Where: Pressure is measured in pascals (Pa), where 1 Pa = 1 N/m². Force is the force applied on the surface (in newtons, N). Area is the … Read more

Draw and explain the force-extension graph for elastic solids.

Force-Extension Graph for Elastic Solids The force-extension graph for an elastic solid (such as a spring) shows the relationship between the applied force and the extension (displacement) of the material. Here’s an explanation of the graph: Graph Overview: X-axis represents the extension or displacement of the solid (measured in meters). Y-axis represents the force applied … Read more

What is Hooke’s law? Illustrate its applications. Also, define and calculate the spring constant.

Hooke’s Law states that the force required to stretch or compress a spring is directly proportional to the displacement (change in length) of the spring from its equilibrium position. Mathematically, it is expressed as: F=k⋅x Where: F is the force applied to the spring (in newtons, N), k is the spring constant (in newtons per meter, … Read more

Define elasticity and elastic limit. Show that a force may produce a change in the size and shape of solids.

Elasticity refers to the ability of a material to return to its original shape and size after being deformed by an external force. When the force is removed, the material will regain its original dimensions if the deformation is within the material’s elastic limit. Elastic limit is the maximum amount of stress or strain that … Read more

How can a small car lifter lift a load heavier than itself?

A small car lifter operates based on Pascal’s law, which states that pressure applied to a confined fluid is transmitted equally in all directions. A hydraulic system in the lifter consists of a small input piston and a larger output piston. When force is applied to the small piston, it creates pressure in the fluid, … Read more

Why do static fluids always exert a force perpendicular to the surface?

In a static fluid, the molecules are in constant random motion, colliding in all directions. When a surface is placed within the fluid, the pressure at any point arises due to the weight of the fluid above it and molecular collisions. These collisions exert forces equally in all directions, but the net force on any … Read more

A spring, having spring constant k when loaded with mass m, is cut into two equal parts. One of the parts is loaded with the same mass m again. What will be its new spring constant?

When a spring of constant k is cut into two equal parts, each part becomes stiffer because the same force causes a greater displacement in a shorter length. The spring constant of each half is given by k’ = 2k. This means that when one of the halves is loaded with the same mass m, … Read more

How are we able to break a metal wire by bending it repeatedly?

When a metal wire is bent repeatedly, it undergoes cyclic stress that weakens its internal structure. Every time it is bent, microscopic cracks develop at the stressed points. These cracks propagate further with each bend, reducing the wire’s strength. Eventually, the accumulated stress surpasses the material’s endurance limit, leading to fracture. This phenomenon is known … Read more

Q12. Differentiate between precision and accuracy.

Ans: Differentiate between precision and accuracy. Precision Accuracy (i) Precision refers to the degree of consistency or reproducibility of measurements. (i) Accuracy refers to the degree of closeness between a measured value and the true or accepted value. (ii) A measurement is precise if repeated measurements under the same conditions yield similar results, regardless of … Read more