Verified Solution • 2025–26 Session moderate

QPages 11-12: Q11: HC Verma: Concepts of Physics - Volume 2 Heat and Temperature Pages 11-12: Q11 Solution: An aluminium sphere is dipped into water at 10�C. If the…

⚠️ Common Exam Traps & Conceptual Pitfalls

Students often treat the buoyant force as fixed, ignoring that $F_b=\rho_{fluid} V_{disp}\,g$ changes when temperature alters both the fluid density and the object's volume. Remember that water’s volume expansion coefficient is far larger than aluminium’s, so as temperature rises $\rho_{water}$ drops more than $V_{sphere}$ grows, causing $F_b$ to decrease.

An aluminium sphere is dipped into water at 10�C. If the temperature is increased, the force of buoyancy

Multiple Choice Options

  • A will increase
  • B will decrease
  • C will remain constant
  • D may increase or decrease depending on the radius of the sphere

Step-by-Step Verified Solution

**Answer:** (b) will decrease. **Step-by-Step Explanation:** When temperature increases, water expands, so its density decreases. The buoyant force is F = __water V_sphere g. If the sphere also expands, its volume increases, but the density of water decreases. For an aluminium sphere, the expansion of the sphere is less than the expansion of water (since water's volume expansion coefficient is much larger than aluminium's). Hence, the buoyant force decreases.

All Questions in this Chapter

QPage 11: Q1 QPage 11: Q2 QPage 11: Q3 QPage 11: Q4 QPage 11: Q5 QPage 11: Q6 QPage 11: Q7 QPage 11: Q8 QPage 11: Q9 QPage 11: Q10 QPage 11: Q11 QPage 11: Q12 QPage 11: Q13 QPage 12: Q1 QPage 12: Q2 QPage 12: Q3 QPage 12: Q4 QPage 12: Q5 QPage 12: Q6 QPages 11-12: Q1 QPages 11-12: Q2 QPages 11-12: Q3 QPages 11-12: Q4 QPages 11-12: Q5 QPages 11-12: Q6 QPages 11-12: Q7 QPages 11-12: Q8 QPages 11-12: Q9 QPages 11-12: Q10 QPages 11-12: Q11 QPages 12-14: Q1 QPages 12-14: Q2 QPages 12-14: Q3 QPages 12-14: Q4 QPages 12-14: Q5 QPages 12-14: Q6 QPages 12-14: Q7 QPages 12-14: Q8 QPages 12-14: Q9 QPages 12-14: Q10 QPages 12-14: Q11 QPages 12-14: Q12 QPages 12-14: Q13 QPages 12-14: Q14 QPages 12-14: Q15 QPages 12-14: Q16 QPages 12-14: Q17 QPages 12-14: Q18 QPages 12-14: Q19 QPages 12-14: Q20 QPages 12-14: Q21 QPages 12-14: Q22 QPages 12-14: Q23 QPages 12-14: Q24 QPages 12-14: Q25 QPages 12-14: Q26 QPages 12-14: Q27 QPages 12-14: Q28 QPages 12-14: Q29 QPages 12-14: Q30 QPages 12-14: Q31 QPages 12-14: Q32 QPages 12-14: Q33 QPages 12-14: Q34

Related Learning Resources & Exam Preparation

Chapter Practice Bank
Practice all topic-wise questions from Heat and Temperature
Reference Textbook Solutions
Explore complete chapter exercises for HC Verma: Concepts of Physics - Volume 2
Competitive PYQ Question Bank
Browse year-wise authentic previous years' questions with solutions
Authentic CBT Mock Tests
Simulate official exam environment with live timer and percentile scoring