Typical on-state voltage drop of a conducting thyristor When an SCR is in the on state and conducting rated current, the approximate voltage drop across it is:

Introduction / Context:
The on-state drop of power devices directly influences conduction losses and heat sink sizing. For SCRs, the drop is relatively low compared with transistors at similar currents.

Given Data / Assumptions:

• Thyristor in full conduction (latch-on), steady current.
• Typical industrial devices at nominal current and temperature.

Concept / Approach:
SCRs exhibit a quasi-constant on-state drop, often around 1 to 2 V depending on current and temperature, due to their PNPN conduction characteristics.

Step-by-Step Solution:
Select the closest nominal value used for loss estimates → ~1 V (sometimes 1–2 V).Rule out obviously excessive values like 10 V or more at rated current.

Verification / Alternative check:
Datasheets list V_T(on) typically in the 1–2 V range for rated currents.

Why Other Options Are Wrong:
10–100 V: Would cause huge losses; not realistic for a conducting SCR.
0.1 V: Too small for SCR technology; closer to low-Rds(on) MOSFETs at modest current.

Common Pitfalls:
Using a single fixed value; real devices vary with current and junction temperature.

Final Answer:
about 1 V