For an organ pipe completely closed at one end, the fundamental frequency is f. What are the frequencies of the next two higher harmonics? MCQ with Answer and Explanation

Explanation:
Work done to charge a capacitor is stored as electrostatic potential energy in the electric field between plates: U = ½QV = ½CV² = Q²/(2C). This energy can be recovered when capacitor discharges. Heat (A) is dissipated in resistance during charging, but ideal capacitor stores energy electrostatically. Memory aid: 'Capacitor energy = ½CV², stored in electric field'. This electrostatics concept is frequently tested in competitive exams. Always distinguish ideal capacitor (no resistance) from real circuits where some energy is lost as heat during charging.

Explanation:
Least count = 1 MSD - 1 VSD. 20 VSD = 19 MSD ⇒ 1 VSD = 19/20 mm = 0.95 mm. LC = 1 - 0.95 = 0.05 mm. Formula: LC = MSD/n where n = vernier divisions. Memory tip: LC = smallest measurable difference = main scale value/vernier divisions. Essential for practical physics questions in competitive exams.

Explanation:
By conservation of momentum: initial momentum = 0 (system at rest). Final momentum: m_bullet×v_bullet + m_gun×v_gun = 0. Thus (0.02 kg)(300 m/s) + (2 kg)(v_gun) = 0 ⇒ 6 + 2v_gun = 0 ⇒ v_gun = -3 m/s. Magnitude is 3 m/s; negative sign indicates opposite direction to bullet. This demonstrates momentum conservation in isolated systems. Memory tip: Recoil velocity = -(m_bullet/m_gun)×v_bullet. Such numerical problems test application of conservation laws, frequently appearing in competitive exams with varying mass ratios and velocities.