A 4 stroke spark ignition engine gave the following results during a test. Number of cylinders 6 Bore of cylinders 90 mm Stroke 80 mm Speed 5000rev/min Fuel consumption rate 0.3dm³ /min Fuel density 750 kg/m³ Calorific value =42MJ/kg Net brake load 180 N Torque arm0.5 m Net indicated area 720 mm² Base length of indicator diagram 60 mm Pressure scale 40kPa/mm Calculate: B.P., I.P., ηbᵦₜₕ ,ηᵢₜₕ, ηₘₑₕ Indicated Power (I.P.) Brake Power
B.P =2∗pi*N∗
ηbᵦₜₕ =B⋅P/mf×C.V.
ηᵢₜₕ,​ = I.P./ mf x C.V.
​ηₘₑₕ = B.P./I.