During the phenonmenon of resonance

Options

A. the amplitude of oscillation becomes large
B. the frequency of oscillation become large
C. the time period of oscillation becomes large
D. All of the above

Explanation

**Step-by-Step Solution:**

1. **Understanding Resonance**: Resonance occurs when an external force or periodic driving frequency matches the natural frequency of a system. This results in a significant increase in the amplitude of oscillation.

2. **Natural Frequency**: Every oscillating system has a natural frequency, which is the frequency at which it tends to oscillate when not subjected to a continuous or repeated external force.

3. **Applied Frequency**: This is the frequency of the external force applied to the system.

4. **Condition for Resonance**: The phenomenon of resonance occurs when the applied frequency equals the natural frequency of the system. Mathematically, this can be expressed as:
\[ f_{applied} = f_{natural} \]

5. **Result of Resonance**: When the above condition is met, the system absorbs energy from the external force efficiently, leading to a dramatic increase in the amplitude of oscillation. This is why during resonance, the amplitude of the oscillation becomes large.

6. **Conclusion**: Therefore, the correct answer to the question about the phenomenon of resonance is that the amplitude of oscillation becomes large when the applied frequency equals the natural frequency.

**Final Answer**: The amplitude of oscillation becomes large during the phenomenon of resonance because the applied frequency is equal to the natural frequency.

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