Criteria S.I. Engine (Petrol or Spark Ignition Engine) C.I. Engine (Diesel or Compression Ignition Engine) Working Cycle Works on Otto Cycle or Constant Volume Cycle. Works on Diesel Cycle. Mixture During Suction Stroke Takes a mixture of air and petrol during the suction stroke. Takes only air during the suction stroke. Fuel Used Uses petrol as fuel. Uses diesel as fuel. Compression Ratio Has a compression ratio that varies from 6 to 10. Has a compression ratio that varies from 16 to 20. Engine Weight and Cost S.I. engines are lighter and cheaper. C.I. engines are heavier and costlier. Initial Cost Initial cost is lower compared to C.I. engines. Initial cost is high due to high compression ratio. Starting Starting is easy. Starting is difficult, especially in cold conditions. ...
•Strain Energy - It is the energy stored in a elastic body under load is called strain energy.
• RESILIENCE - It is the capacity of elastic body for doing work when load is removed on elastic body.
Example - Spring
• PROOF RESILIENCE - It is the maximum strain energy stored in a elastic body upto elastic limit is called proof Resilience.
• Modulus of Resilience - It is the ratio of proof Resilience and Volume of the body.
MOR - PR/V
• Proof Load - It is the maximum load applied to the elastic body without its parmanent deformation is called proof load.