The thermal efficiency of a steam plant is defined as ________.
1
the ratio of heat of combustion of coal to the heat equivalent of mechanical energy transmitted to the turbine shaft
2
the ratio of heat equivalent of electrical output to the heat of combustion of coal
3
the ratio of heat equivalent of mechanical energy transmitted to the turbine shaft to the heat of combustion of coal
4
the ratio of heat of combustion of coal to the heat equivalent of electrical output
5
Question Not Attempted