Solve this multiple-choice question and choose the correct option.

ConceptIn cut-off governing, the governor varies the admission period (cut-off) so that the quantity/volume of steam admitted each cycle changes. The supply pressure is not deliberately throttled (unlike throttle governing). Why others are incorrect Pressure variation is characteristic of throttle governing, not cut-off governing. Temperature is not the control variable; it is a function of boiler/superheater operation. Key takeawayCut-off governing controls engine power by metering steam quantity (admission duration), not by throttling pressure.

Cut-off governing of steam engines: what parameter is varied to control output? Context: In cut-off governing, the point of admission is altered while speed/load change, without throttling the inlet pressure. Choose what is actually controlled under cut-off governing.

Mechanical Engineering Steam Boilers and Engines Difficulty: Easy

Choose an option

A

Volume (quantity) of intake steam admitted per cycle by changing cut-off
B

Pressure of intake steam at the throttle valve
C

Temperature of intake steam at the superheater outlet
D

All of these simultaneously

Answer

Correct Answer: Volume (quantity) of intake steam admitted per cycle by changing cut-off

Explanation

ConceptIn cut-off governing, the governor varies the admission period (cut-off) so that the quantity/volume of steam admitted each cycle changes. The supply pressure is not deliberately throttled (unlike throttle governing).

Why others are incorrect

Pressure variation is characteristic of throttle governing, not cut-off governing.
Temperature is not the control variable; it is a function of boiler/superheater operation.

Key takeawayCut-off governing controls engine power by metering steam quantity (admission duration), not by throttling pressure.