Otto cycle fuel introduction — is external fuel injection required? State whether the following is correct: Engines working on the ideal Otto cycle do not require high-pressure fuel injection by an external source into the cylinder (mixture is prepared before admission).

Introduction / Context:
The ideal Otto cycle models a homogeneous, premixed charge that is compressed and then ignited by a spark. Historically, spark-ignition engines used carburettors to meter fuel upstream; modern SI uses port or direct injection but still does not rely on diesel-like high-pressure injection to trigger ignition.

Given Data / Assumptions:

• Otto cycle = constant-volume heat addition applied to a premixed homogeneous charge.
• Ignition source is a spark, not auto-ignition by compression.
• “External source injection” here refers to diesel-style high-pressure in-cylinder injection being essential for operation.

Concept / Approach:
In the classical Otto framework, fuel is introduced and mixed with air before the intake valve, and the cylinder draws in the mixture. Thus, no high-pressure, in-cylinder “external” injection system is required to achieve combustion. While many modern SI engines use injection (port or DI) for mixture preparation and control, ignition still requires a spark and does not depend on compression ignition or mandatory diesel-type injection hardware.

Step-by-Step Solution:

Verification / Alternative check:
Carburetted engines fully satisfy the ideal Otto premise. Port-fuel-injected SI engines still premix before ignition; direct-injection SI times fuel delivery but relies on a spark, not compression-induced auto-ignition.

Why Other Options Are Wrong:

• No: Implies injection is required for Otto-cycle operation, which is not inherent.
• Conditional options: The ideal cycle definition is general and not limited to specific hardware era.

Common Pitfalls:
Confusing “fuel injection present” with “fuel injection required for ignition.” SI uses a spark to initiate combustion; the presence of injectors does not change the fundamental ignition mode.

Final Answer:
Yes