Elastic deformation MCQs With Answer are essential revision tools for B. Pharm students studying material behavior in pharmaceutical formulations. This concise, SEO-friendly introduction covers key concepts like elastic deformation, Hooke’s law, stress and strain, Young’s modulus, elastic limit, viscoelasticity, and implications for tablet compression and polymeric excipients. Understanding elastic vs plastic deformation and elastic recovery helps predict tablet capping, dimensional stability, and mechanical performance of drug delivery systems. These targeted MCQs with answers reinforce theory, formulas, units, testing methods, and practical pharmaceutical applications to build exam-ready knowledge and lab preparedness. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. What is the defining characteristic of elastic deformation?
- The material returns to its original shape after load removal
- The material permanently changes shape after load removal
- The material fractures under small load
- The material flows like a liquid under stress
Correct Answer: The material returns to its original shape after load removal
Q2. Which law describes the linear relationship between stress and strain within the elastic region?
- Newton’s law
- Hooke’s law
- Faraday’s law
- Poisson’s law
Correct Answer: Hooke’s law
Q3. What is the SI unit of stress?
- Pascal (Pa)
- Newton (N)
- Meter (m)
- Joule (J)
Correct Answer: Pascal (Pa)
Q4. Young’s modulus measures which property?
- Resistance to shear deformation
- Stiffness under tensile or compressive loading
- Resistance to fracture
- Rate of viscous flow
Correct Answer: Stiffness under tensile or compressive loading
Q5. Which parameter is defined as strain per unit applied stress in the elastic region?
- Young’s modulus
- Elastic modulus
- Poisson’s ratio
- Compliance
Correct Answer: Compliance
Q6. What does the elastic limit represent?
- The stress at which permanent deformation begins
- The stress at which fracture occurs
- The maximum load a machine can apply
- The temperature at which material melts
Correct Answer: The stress at which permanent deformation begins
Q7. In tablet compression, excessive elastic recovery can cause which problem?
- Improved dissolution
- Capping and lamination
- Increased disintegration time
- Enhanced tablet color uniformity
Correct Answer: Capping and lamination
Q8. Poisson’s ratio relates which two quantities?
- Stress and time
- Lateral strain to axial strain
- Temperature change to strain
- Stress to fracture toughness
Correct Answer: Lateral strain to axial strain
Q9. Which modulus quantifies resistance to shear deformation?
- Young’s modulus
- Bulk modulus
- Shear modulus (G)
- Compliance modulus
Correct Answer: Shear modulus (G)
Q10. Bulk modulus is most relevant to which deformation?
- Volumetric compression
- Tensile stretching
- Simple shear
- Bending
Correct Answer: Volumetric compression
Q11. Which of the following describes viscoelastic behavior?
- Instant elastic recovery only
- Time-dependent strain with both elastic and viscous components
- Purely plastic flow
- Brittle fracture without deformation
Correct Answer: Time-dependent strain with both elastic and viscous components
Q12. Creep is best defined as:
- Instantaneous elastic deformation under load
- Time-dependent deformation under constant stress
- Immediate fracture on loading
- Temperature-induced swelling
Correct Answer: Time-dependent deformation under constant stress
Q13. Which instrument is commonly used to measure stress–strain behavior of tablets and polymers?
- Chromatograph
- Universal testing machine (UTM)
- Mass spectrometer
- pH meter
Correct Answer: Universal testing machine (UTM)
Q14. What is the proportional limit on a stress–strain curve?
- The point where stress and strain are no longer linearly related
- The point of material fracture
- The maximum stress measured
- The stress at zero strain
Correct Answer: The point where stress and strain are no longer linearly related
Q15. An elastic material has which of the following after unloading below elastic limit?
- Permanent set
- Elastic recovery to original dimensions
- Increased porosity
- Phase transition
Correct Answer: Elastic recovery to original dimensions
Q16. Which factor does NOT significantly affect elastic properties of a polymeric excipient?
- Temperature
- Humidity
- Particle color
- Molecular weight
Correct Answer: Particle color
Q17. Elastic strain energy stored in a deformed body is given by which expression for linear elastic behavior?
- 0.5 × stress × strain × volume
- stress × strain
- stress / strain
- strain × time
Correct Answer: 0.5 × stress × strain × volume
Q18. Which phenomenon is a consequence of elastic recovery in compressed tablets during ejection?
- Enhanced tensile strength
- Swelling leading to weight gain
- Stickiness to punches and possible sticking defects
- Immediate dissolution acceleration
Correct Answer: Stickiness to punches and possible sticking defects
Q19. Which of the following materials exhibits predominantly elastic behavior up to a high stress?
- Rubber at small strains
- Lead
- Polyethylene at high temperature
- Clay slurry
Correct Answer: Rubber at small strains
Q20. The slope of the linear portion of a tensile stress–strain curve represents:
- Yield strength
- Young’s modulus
- Fracture toughness
- Hardness number
Correct Answer: Young’s modulus
Q21. Poisson’s ratio for most solids typically lies in which range?
- 0 to 0.5
- 1.0 to 2.0
- -1.0 to -0.5
- 0.6 to 1.0
Correct Answer: 0 to 0.5
Q22. Which test determines compressive elastic properties of a tablet core?
- Hardness tester under zero load
- Tensile tester with adhesive grips
- Diametral compression (Brazilian) test
- Disintegration test
Correct Answer: Diametral compression (Brazilian) test
Q23. Elastic recovery is most problematic in which tablet manufacturing stage?
- Granulation drying
- Punch ejection and post-ejection handling
- Coating storage only
- Packaging labeling
Correct Answer: Punch ejection and post-ejection handling
Q24. Which term describes the stress at which material yields and plastic deformation begins?
- Elastic modulus
- Yield strength
- Fracture energy
- Creep limit
Correct Answer: Yield strength
Q25. Hysteresis in a load-unload cycle indicates what property?
- No energy loss during cycle
- Energy dissipation due to viscoelasticity
- Infinite elastic modulus
- Immediate fracture on unloading
Correct Answer: Energy dissipation due to viscoelasticity
Q26. For small deformations, stress = E × strain. In this equation, E stands for:
- Energy
- Young’s modulus
- Elastic limit
- Electrical conductivity
Correct Answer: Young’s modulus
Q27. Which process describes permanent change after passing elastic limit?
- Elastic recovery
- Plastic deformation
- Reversible swelling
- Viscous flow that fully recovers
Correct Answer: Plastic deformation
Q28. In pharmaceutical polymers, cross-linking typically affects elasticity by:
- Decreasing stiffness and increasing flowability
- Increasing stiffness and reducing elastic elongation
- Turning them into liquids
- Reducing molecular weight only
Correct Answer: Increasing stiffness and reducing elastic elongation
Q29. Which is a common consequence of high elastic modulus in excipients used for brittle tablets?
- Improved plastic deformation
- Higher tendency to fracture or cap
- Lower friability
- Enhanced lubrication
Correct Answer: Higher tendency to fracture or cap
Q30. The proportional limit is typically:
- Higher than the elastic limit
- Identical to fracture point
- The end of linear elastic behavior and often close to elastic limit
- Unrelated to stress–strain curve
Correct Answer: The end of linear elastic behavior and often close to elastic limit
Q31. Which measurement helps quantify elastic recovery after tablet compression?
- Percent porosity only
- Dimension change percentage after decompression
- Colorimetry
- Moisture content only
Correct Answer: Dimension change percentage after decompression
Q32. Elastic deformation is generally reversible because atomic bonds in the material:
- Break permanently under small strain
- Stretch but return to original configuration when load removed
- Become ionic
- Undergo chemical change
Correct Answer: Stretch but return to original configuration when load removed
Q33. Which of the following increases elastic recovery in a compressed tablet?
- Use of highly plastic binders
- High elastic filler content like microcrystalline cellulose
- Higher lubricant concentration only
- Low compression force always
Correct Answer: High elastic filler content like microcrystalline cellulose
Q34. Which phenomenon is reversed on unloading in the purely elastic region?
- Plastic flow
- Elastic strain
- Permanent necking
- Phase separation
Correct Answer: Elastic strain
Q35. Which term describes failure after cyclic loading due to repeated elastic and plastic deformation?
- Fatigue
- Creep rupture
- Instant fracture
- Yielding without damage
Correct Answer: Fatigue
Q36. Which parameter is most relevant for designing elastic springs in lab apparatus?
- Hardness number
- Young’s modulus
- Thermal conductivity
- Optical clarity
Correct Answer: Young’s modulus
Q37. Stress relaxation in viscoelastic materials refers to:
- Increase in stress over time under constant strain
- Decrease in stress over time under constant strain
- Immediate fracture under strain
- Constant stress under changing strain
Correct Answer: Decrease in stress over time under constant strain
Q38. In compression testing of powders, which behavior indicates elastic predominance?
- Large permanent densification on unloading
- Significant rebound in tablet height on decompression
- Immediate brittle fracture during compression
- No change in height during compression
Correct Answer: Significant rebound in tablet height on decompression
Q39. Which material property can be reduced by adding plasticizers to a polymer formulation?
- Elasticity at room temperature
- Tensile strength only without affecting elasticity
- Glass transition temperature and stiffness, increasing flexibility
- Mass density exclusively
Correct Answer: Glass transition temperature and stiffness, increasing flexibility
Q40. Which of the following best differentiates elastic from plastic deformation on a microscopic level?
- Elastic involves dislocation movement; plastic does not
- Elastic involves reversible bond stretching; plastic involves permanent bond rearrangement or dislocation motion
- Plastic is reversible and elastic is permanent
- Both are always identical processes
Correct Answer: Elastic involves reversible bond stretching; plastic involves permanent bond rearrangement or dislocation motion
Q41. Which of the following is a pharmaceutically relevant example of elastic deformation?
- Capping due to plastic flow only
- Tablet rebound after ejection causing weight variation
- Complete dissolution in water
- Chemical degradation of API
Correct Answer: Tablet rebound after ejection causing weight variation
Q42. Increasing compression dwell time typically affects elastic and plastic behavior by:
- Reducing time for plastic flow
- Allowing more plastic deformation and reducing elastic recovery
- Eliminating both elastic and plastic deformation
- Only changing tablet color
Correct Answer: Allowing more plastic deformation and reducing elastic recovery
Q43. Which modulus would you use to describe response to uniform hydrostatic pressure?
- Young’s modulus
- Shear modulus
- Bulk modulus
- Fracture modulus
Correct Answer: Bulk modulus
Q44. In a stress–strain experiment, which observation indicates yield point phenomena?
- Complete linearity up to fracture
- A sudden drop or plateau in stress after proportional limit
- Immediate increase in stress with no plateau
- No measurable strain
Correct Answer: A sudden drop or plateau in stress after proportional limit
Q45. Which statement about elastic modulus and temperature is generally true for polymers?
- Modulus increases with increasing temperature
- Modulus decreases as temperature approaches glass transition
- Modulus is independent of temperature
- Modulus becomes infinite at elevated temperatures
Correct Answer: Modulus decreases as temperature approaches glass transition
Q46. Which testing parameter helps separate elastic and plastic contributions during compaction?
- Compression speed only
- Unloading-reloading cycles and analysis of rebound
- Tablet color measurement
- pH of granulation liquid
Correct Answer: Unloading-reloading cycles and analysis of rebound
Q47. A material that shows immediate elastic response and negligible permanent set is called:
- Viscoplastic
- Brittle elastic
- Elastic (ideally elastic)
- Rheological fluid
Correct Answer: Elastic (ideally elastic)
Q48. Which of the following best reduces tablet elastic recovery during formulation?
- Increase elastic filler proportion
- Use more plastic binders and increase dwell time
- Reduce compression force drastically
- Avoid granulation entirely
Correct Answer: Use more plastic binders and increase dwell time
Q49. The area under the unloading curve in a load-unload cycle represents:
- Total elastic energy stored forever
- Work done by external agent only
- Elastic energy recovered; difference to loading area is dissipated energy
- Irreversible chemical energy
Correct Answer: Elastic energy recovered; difference to loading area is dissipated energy
Q50. Which property is most desirable for an excipient to minimize tablet capping due to elastic recovery?
- High elastic modulus and high elasticity
- Balanced plasticity with moderate compressibility
- Complete brittleness with no plasticity
- Extremely low density only
Correct Answer: Balanced plasticity with moderate compressibility
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