39) The pre-ignition occurs before the spark is produced whereas detonation develops after the introduction of spark.

40) The energy released during the fission of one atom of Uranium - 235 in million electron volts is about

41) Morse test can be conducted for

42) The basic requirement of a good combustion chamber is

43) In a four stroke cycle petrol engine, the charge is compressed when both the valves (i.e. inlet valve and exit valve) are closed,