Which engine operates more efficiently than standard turbojets by producing greater thrust?

The turbofan engine operates more efficiently than standard turbojets primarily due to its design, which includes a large fan at the front that generates additional thrust. This fan accelerates a larger volume of air compared to a turbojet, allowing the engine to produce more thrust while using less fuel. This efficiency is particularly effective at subsonic and transonic speeds, where turbofans are commonly used in commercial aviation.

In contrast to turbojets, which propel an aircraft solely by expelling high-speed exhaust gases, turbofans utilize a bypass system where a significant portion of the air that is drawn into the engine bypasses the combustion chamber. Since this bypassed air moves at a lower velocity, it enhances the efficiency of the engine at cruising speeds. This design results in quieter operation and reduced fuel consumption, which is particularly advantageous for airlines looking to minimize operational costs.

Other options, such as turboprops, ramjets/scramjets, and propfans, do have specific uses and efficiency gains in certain conditions, but they do not match the broader efficiency benefits of turbofans, especially in the context of commercial aviation.