Answer:
The lamp rattles because close resonant frequency.
Step-by-step explanation:
The phenomenon of increased amplitude is known as resonance when the frequency of a periodically applied force is equal to or close to the natural frequency of the system it affects. When a resonant frequency oscillating force is applied to a dynamic system, the system oscillates with greater amplitude than when the same force is applied at non-resonant frequencies.
Resonant frequencies or resonance frequencies of the system are frequencies when the response amplitude is at a relative maximum. Due to the storage of vibrational energy, small periodic stresses at a resonance frequency of the system can cause significant amplitude oscillations in the system.
Thereforee, the lamp rattles because close resonant frequency.