NEET Practice Questions (MCQs) with Answers & Solutions

The provided text states, 'The elastic behaviour of materials plays an important role in engineering design. For example...Can we design an aeroplane which is very light but sufficiently strong?' This directly links the elastic behavior of materials to the design of light yet strong structures like airplane wings.

The text poses the question: 'Why does a railway track have a particular shape like I?' While the direct answer isn't given, implicitly, this shape is chosen due to elastic behavior considerations to withstand forces efficiently. I-beams are engineered to have high strength-to-weight ratios, resisting bending and buckling effectively, which is a key application of elastic behavior in structural design.

The 'POINTS TO PONDER' section clarifies: 'In daily life, we feel that a material which stretches more is more elastic, but it is a misnomer. In fact, material which stretches to a lesser extent for a given load is considered to be more elastic.' This contradicts common intuition and highlights the scientific definition of elasticity.

The text states, 'The elastic behaviour of materials plays an important role in engineering design. For example, while designing a building, knowledge of elastic properties of materials like steel, concrete etc. is essential.' This indicates that understanding how these materials deform under stress and return to their original shape is crucial for structural integrity and safety.

The 'POINTS TO PONDER' section notes: 'A material with large value of Young’s modulus requires a large force to produce small changes in its length.' This property is desirable for structural components where minimal deformation under stress is critical.

The 'POINTS TO PONDER' section explicitly states: 'Metals have larger values of Young’s modulus than alloys and elastomers.' Also, 'Young’s modulus and shear modulus are relevant only for solids since only solids have lengths and shapes.'

The text asks, 'Can we design an artificial limb which is lighter but stronger?' This question highlights the practical application of elastic properties in balancing weight and strength for improved user experience and functionality in prosthetics.

The text states, 'The same is true in the design of bridges, automobiles, ropeways etc.' This implies that, similar to structures like bridges, ropeways rely on the elastic behavior of strong solid materials (like steel cables) to safely support loads and withstand stresses.

The introductory paragraph explains elasticity: 'The property of a body, by virtue of which it tends to regain its original size and shape when the applied force is removed, is known as elasticity.' Materials like steel are excellent for springs because they possess high elasticity and exhibit a well-defined elastic region, ensuring they return to their original form.

According to the NCERT text, 'Thus, we find that the acceleration of an object in uniform circular motion is always directed towards the centre of the circle.' Also, it states that 'The direction of velocity v is along the tangent to the circle at every point. The acceleration is directed towards the centre of the circle. Since this direction changes continuously, acceleration here is not a constant vector.' Therefore, the acceleration is always directed towards the center.