A vibrating tuning fork produces sound waves. These waves are MCQ with Answer and Explanation

Explanation:
Infrasound < 20 Hz, ultrasound > 20 kHz.

Explanation:
e = √(h₂/h₁) = √(1.25/5) = √0.25 = 0.5.

Explanation:
Energy stored in capacitor U = ½CV² = ½QV = Q²/(2C). This derives from work done to charge the capacitor against increasing voltage. Option A has wrong dimensions (energy should be joules, CV is coulomb-volt = joule, but missing factor ½); C and D are dimensionally incorrect. Memory tip: 'Capacitor energy = ½CV², analogous to spring energy ½kx²'. This formula-based question tests electrostatics knowledge, frequently appearing in competitive exams. Always recall the three equivalent forms and choose based on given quantities.