Coupled PendulumsHardQuestion 31192
Question
Two identical pendulums weakly coupled show 'beats' phenomenon because:
- ATheir frequencies are exactly equal
- BTwo normal mode frequencies are slightly different — energy oscillates between themCorrect
- CCoupling removes all oscillation
- DMass of bob changes
Correct answer
Two normal mode frequencies are slightly different — energy oscillates between them
Explanation
Coupling splits the degenerate frequency into two close frequencies ω₁ and ω₂. Beat frequency = |ω₁−ω₂|. Energy transfers from one pendulum to the other at the beat frequency.