81) An atom bomb utilises uncontrolled nuclear fission.

82) The ratio of the brake power to the indicated power is called

83) The increase of efficiency of a compression ignition engine, as the load decreases, is due to

84) A turbo-jet does not require a turbine to drive the compressor.

85) For the same maximum pressure and heat input, the exhaust temperature of petrol engine is __________ than that of diesel engine.