The mechanical efficiency ( m) of the engine is given by

• A. <img src="/_files/images/mechanical-engineering/ic-engines-and-nuclear-power-plants/347-163-1.png">
• B. <img src="/_files/images/mechanical-engineering/ic-engines-and-nuclear-power-plants/347-163-2.png">
• C. <img src="/_files/images/mechanical-engineering/ic-engines-and-nuclear-power-plants/347-163-3.png">
• D. none of these