The highest frequency that is returned to Earth when transmitted vertically under given ionospheric conditions is called the ____________
A. critical angle
B. maximum usable frequency
C. critical frequency
D. optimum working frequency
C
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Which type of space heater is most likely to NOT pass a local inspection?
A) Vented B) Gravity operated C) Unvented D) Catalytic
How is the energy efficiency ratio (EER) calculated?
A) The output in Btuh is divided by the input in watts. B) The output in Btuh is multiplied by the input in watts. C) The input in watts is divided by the output in Btuh. D) The input in watts is added to the output in Btuh.
Always perform a visual inspection of a pump for problems _____
A) at the end of the shift B) once per week C) at the beginning of the shift D) when the pump is operating at normal temperature
An automotive alternator is rated 500 VA and 20 V. It delivers its rated voltamperes at a power factor of 0.85. The resistance per phase is 0.05 ?, and the field takes 2 A at 12 V. If the friction and windage loss is 25 W and the core loss is 30 W, calculate the percent efficiency under rated conditions.
What will be an ideal response?