Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
328 views
in General by (115k points)
closed by
The stroke and bore of a four stroke spark ignition engine are 250 mm and 200 mm respectively. The clearance volume is 0.001 m3. If the specific heat ratio γ = 1.4, the air-standard cycle efficiency of the engine is 
1. 46.40%
2. 56.10%
3. 58.20%
4. 62.80%

1 Answer

0 votes
by (152k points)
selected by
 
Best answer
Correct Answer - Option 3 : 58.20%

SI engine

clearance volume, VC = 0.001 m2 

stroke length, L = 250 mm = 0.25 m

bore dia, d = 200 mm = 0.2 m

specific heat ratio, γ = 1.4

\(Stroke\;Volume,\;\;{V_s} = \frac{\pi }{4}{D^2}L \\= \frac{\pi }{4} \times {0.2^2} \times 0.25 = 0.00785\)

\(Compression\;Ratio\;,r = 1 + \frac{{{V_s}}}{{{V_c}}} \\= 1 + \frac{{0.00785}}{{0.001}} = 8.85\)

\(efficiency\;\;\eta = 1 - \frac{1}{{{r^{{\rm{\gamma }} - 1}}}}\)

\(= 1 - \frac{1}{{{{8.85}^{\left( {1.4 - 1} \right)}}}}\)

\(= 1 - \frac{1}{{{{8.85}^{0.4}}}}\)

= 0.5819

η ≈ 58.20%

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...