**Category:** Electromagnetism  
**Subtype:** Capacitors  
**Problem Description:** This problem involves calculating the charge on a capacitor when it is connected to a voltage source that is lower than its rated maximum voltage. Specifically, it asks for the percentage of the maximum charge that the capacitor can hold when charged to a given voltage.  

**Key Concepts:**  
- The maximum charge \( Q_{max} \) a capacitor can hold is given by the formula \( Q_{max} = C \cdot V_{max} \), where \( C \) is the capacitance and \( V_{max} \) is the maximum voltage.  
- The charge \( Q \) on the capacitor when charged to a voltage \( V \) is given by \( Q = C \cdot V \).  
- The problem requires finding the ratio of \( Q \) to \( Q_{max} \) and expressing it as a percentage.  

**Objective:** Find the percentage of the maximum charge that the capacitor can hold when charged to 150 V.