Assertion–Reason (GTO vs SCR circuitry) Assertion (A): A GTO-based power converter can be more compact than an SCR-based converter. Reason (R): A Gate-Turn-Off thyristor (GTO) can be turned off by applying an appropriate negative gate current pulse.

Introduction / Context:
Classic SCR inverters require commutation networks (auxiliary capacitors, inductors, and switches) to force device current to zero for turn-off. GTOs, by contrast, can be turned off through the gate, reducing or eliminating bulky commutation circuitry and thus enabling more compact designs (subject to snubber needs).

Given Data / Assumptions:

• SCRs need forced (or line) commutation unless self-commutated devices are used.
• GTOs accept negative gate current to extract carriers and turn off.
• Packaging and magnetics volume are major contributors to size.

Concept / Approach:

By eliminating large commutation components, GTO converters can achieve a smaller footprint for similar ratings. Although GTOs still need snubbers and robust gate drives, the absence of a full commutation network is the primary reason for compactness.

Step-by-Step Solution:

Verification / Alternative check:

Topological comparisons in textbooks show series/parallel inverters (SCR) with sizeable commutation components versus GTO/VSC drives with smaller magnetics at similar power levels.

Why Other Options Are Wrong:

• Options B–D fail because either R would not explain A or one of the statements would be false.

Common Pitfalls:

Assuming GTOs never need snubbers; in practice, snubbering and strong gate drives are still required, but the commutation network bulk is avoided.

Final Answer:

Both A and R are correct and R is correct explanation of A