Using a diesel engine indicator P-V diagram,...

Question 1 of 270705eccefa1bacbc34ba4d473f6

Using a diesel engine indicator P-V diagram, the cylinder mean effective pressure is calculated to be 21.3 kg/cm². What is the scale of the spring used on the indicator if the diagram area is 18.46 cm² with a length of 13 cm?

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Question 1 of 27070

🔍 Key Concepts

• Relationship between mean effective pressure, indicator diagram area, and spring scale for a diesel indicator • How the length of the diagram affects the pressure calculation (pressure is proportional to vertical height vs. horizontal length used for averaging) • Unit consistency when working in kg/cm², cm², and cm

💭 Think About

• Recall or derive the formula that links mean effective pressure to the indicator diagram using area, length, and spring scale. Then algebraically solve that formula for the spring scale. • Think about what the spring scale physically represents: how many kg/cm² of pressure correspond to a unit vertical movement on the diagram, and how that ties to the measured area and length. • After rearranging the formula, plug in the given numbers carefully and simplify step by step, then compare your computed value with the multiple-choice options.

✅ Before You Answer

• Be sure you are using the correct basic relationship: Mean Effective Pressure ∝ (Diagram Area × Spring Scale) / Diagram Length. • Check that your units cancel properly so that the result for the spring scale has units of kg/cm (not kg/cm²). • After calculating, verify that your numerical result is close to one of the listed options; if it falls between two, recheck your arithmetic and formula.