N-type semi-conductor material is obtained by doping with

A. Mechanical energy into heat energy B. Heat energy into mechanical energy C. Mechanical energy into sound energy D. None of the above

A. Water cooled B. Air cooled C. Oil cooled D. None of these

A. 1 : 4 - 1 : 10 B. 1 : 12 - 1 : 22 C. 3 : 5 - 5 : 10 D. 5: 12 - 5: 22

A. High volume combustion engine B. Low volume combustion engine C. Constant volume combustion engine D. No volume combustion engine