Question

Which of the following graphs represent the variation of mechanical efficiency v/s brake power of the engine ?

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

(1) As we know that ${\eta }_m=\frac{B.P}{I.P}$

If, $B.P=0$

$\Rightarrow {\eta }_m=0$

${\eta }_m=\frac{B.P}{I.P}$

As we know that with increase in B.P.${\eta }_m$ increases but max. value of ${\eta }_m$ cannot go beyond 100%, So after a particular value with increases in B.P. ${\eta }_m$ remains almost constant.