Answer: C: 60-100mA.
Answer analysis: When considering the conventional current of LED lamp beads, we need to understand the working characteristics and common specifications of LED lamp beads. As a semiconductor device, LED (light-emitting diode) usually has a low operating current to ensure efficient light emission and long life.
Now, let's analyze one by one according to the given options:
A: 0-20mA: This range is on the low side. Although some low-power or specially designed LED lamp beads may work within this current range, it is not the conventional working current of most LED lamp beads.
B: 20-30mA: This range is closer to the conventional working current of some low-power LED lamp beads, but considering the development and wide application of LED technology, many LED lamp beads may require higher current to achieve the desired brightness and effect.
C: 60-100mA: This range is suitable for medium to high-power LED lamp beads, especially those used for lighting, backlighting or indicator lights that require higher brightness.
D: 30-60mA: Although this range also applies to some LED lamp beads, it may not cover the conventional operating current of medium to high power LED lamp beads as widely as option C.
In actual applications, the operating current of LED lamp beads depends on many factors such as its power, packaging form, luminous efficiency, and required brightness and color. However, for most conventionally applied LED lamp beads, the current range of 60-100mA is a relatively common and reasonable choice.
Therefore, the correct answer is C: 60-100mA. This range covers the conventional operating current of many medium to high power LED lamp beads. But please note that the specific operating current should be determined according to the specifications and application requirements of the LED lamp beads.