【单选题】The input power to a device is 5000 W at 400 V. The output power of the device is 750 W, and the output impedance is 25 Ω. Calculate the power gain in decibels.
【单选题】Good table manners are back Candlelight bathes the restaurant guests in a friendly light, the menu is about to be served. Some guests are prepared to eat while others are looking around with nervous g...
【单选题】Under the condition of grasping the output value of the base period and the individual indices of the outputs of various products, which index should be used to calculate the total output index?