Specific mass of gas turbine vs. reciprocating I.C. engine For approximately the same power output, the mass of a gas turbine plant per kW developed is about __________ compared with that of a reciprocating internal combustion engine.

Introduction / Context:
One advantage of gas turbines is their high power-to-weight ratio, which is critical in aviation and mobile applications. This question compares the specific mass (kg per kW) of gas turbines to reciprocating I.C. engines at similar output scales.

Given Data / Assumptions:

• Comparable technology levels and materials.
• Continuous-flow gas turbine versus multi-cylinder reciprocating engine.
• Accessory mass differences are ignored for a first-order estimate.

Concept / Approach:
Gas turbines deliver smooth continuous torque with far fewer moving parts per unit power, allowing high rotational speeds and compact rotors. Reciprocating engines require heavy crankshafts, pistons, and blocks to handle cyclic loads, increasing mass for the same output.

Step-by-Step Solution:
Identify governing factor: power-to-weight ratio is higher for turbines due to continuous combustion and high rpm capability.Industry comparisons often cite gas turbines weighing a small fraction of comparable I.C. engines.Among the options, ‘‘one-sixth’’ best represents the typical order-of-magnitude advantage.

Verification / Alternative check:
Aero and industrial turbine datasheets show significantly lower specific mass than piston engines at similar outputs, validating the selection.

Why Other Options Are Wrong:
“The same” and “one-half” understate the advantage; “one-fourth” is closer but still typically conservative relative to many practical comparisons.

Common Pitfalls:
Ignoring application context; actual ratios vary with scale and design, but the turbine advantage remains pronounced.

Final Answer:
one-sixth