When does resonance occur? when the frequency of a forced vibration equals the natural frequency when the frequency of a forced vibration is greater than the natural frequency when two waves of the same frequency interfere when two waves of slightly different frequencies interfere nextreset

Resonance = When the frequency of a forced vibration equals the natural frequency

Explanation:

Resonance occurs when the frequency at which the force is applied becomes equal to the natural frequency of the system on which it acts. At resonance, the system will oscillate with larger amplitude. The frequency at which resonance occurs is called resonant frequency.

Hence, the correct option is (a) " when the frequency of a forced vibration equals the natural frequency ".

cell differentiation  is how generic embryonic  cells  become specialized  cells. this occurs  through a process called gene expression. gene expression is the specific combination of genes that are turned on or off (expressed or repressed), and this is what dictates how a  cell  functions.

explanation:

layers of the earth affect the waves and these effects are seen on instruiments such as seimometers