Verified Solution • 2025–26 Session moderate

QPage 383: Q3: HC Verma: Concepts of Physics - Volume 2 Bohr's Model and Physics of the Atom Page 383: Q3 Solution: Suppose, the electron in a hydrogen atom makes transition from…

⚠️ Common Exam Traps & Conceptual Pitfalls

Students often mistakenly calculate the difference in total angular momentum ($\Delta L = L_3 - L_2$) or use the orbital radius, but the problem requires estimating the torque based on the fundamental quantum of angular momentum ($\hbar \approx 10^{-34} \text{ J s}$) transferred during the transition, not the classical change in orbital angular momentum.

Suppose, the electron in a hydrogen atom makes transition from n=3n = 3 to n=2n = 2 in 10−810^{-8} s. The order of the torque acting on the electron in this period, using the relation between torque and angular momentum as discussed in the chapter on rotational mechanics is

Multiple Choice Options

  • A 10−34 N m10^{-34} \text{ N m}
  • B 10−24 N m10^{-24} \text{ N m}
  • C 10−42 N m10^{-42} \text{ N m}
  • D 10−8 N m10^{-8} \text{ N m}

Step-by-Step Verified Solution

**Answer:** (a) 10___ N m. **Step-by-Step Explanation:** Torque = _L/_t. _L = _ = 1.05 _ 10___ J s. _t = 10__ s. Torque � 10___ N m. Standard: 10___.

All Questions in this Chapter

QPage 383: Q1 QPage 383: Q2 QPage 383: Q3 QPage 383: Q4 QPage 383: Q5 QPage 383: Q6 QPage 383: Q7 QPage 383: Q8 QPage 383: Q9 QPage 383: Q10 QPage 383: Q11 QPage 383: Q12 QPage 383: Q13 QPages 382-383: Q1 QPages 382-383: Q2 QPages 382-383: Q3 QPages 382-383: Q4 QPages 382-383: Q5 QPages 382-383: Q6 QPages 382-383: Q7 QPages 382-383: Q8 QPages 382-383: Q9 QPages 382-383: Q10 QPages 383-384: Q1 QPages 383-384: Q2 QPages 383-384: Q3 QPages 383-384: Q4 QPages 383-384: Q5 QPages 383-384: Q6 QPages 384-386: Q1 QPages 384-386: Q2 QPages 384-386: Q3 QPages 384-386: Q4 QPages 384-386: Q5 QPages 384-386: Q6 QPages 384-386: Q7 QPages 384-386: Q8 QPages 384-386: Q9 QPages 384-386: Q10 QPages 384-386: Q11 QPages 384-386: Q12 QPages 384-386: Q13 QPages 384-386: Q14 QPages 384-386: Q15 QPages 384-386: Q16 QPages 384-386: Q17 QPages 384-386: Q18 QPages 384-386: Q19 QPages 384-386: Q20 QPages 384-386: Q21 QPages 384-386: Q22 QPages 384-386: Q23 QPages 384-386: Q24 QPages 384-386: Q25 QPages 384-386: Q26 QPages 384-386: Q27 QPages 384-386: Q28 QPages 384-386: Q29 QPages 384-386: Q30 QPages 384-386: Q31 QPages 384-386: Q32 QPages 384-386: Q33 QPages 384-386: Q34 QPages 384-386: Q35 QPages 384-386: Q36 QPages 384-386: Q37 QPages 384-386: Q38 QPages 384-386: Q39 QPages 384-386: Q40 QPages 384-386: Q41 QPages 384-386: Q42 QPages 384-386: Q43 QPages 384-386: Q44 QPages 384-386: Q45 QPages 384-386: Q46

Related Learning Resources & Exam Preparation

Chapter Practice Bank
Practice all topic-wise questions from Bohr's Model and Physics of the Atom
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