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【判断题】

超声波换能器采用石英或陶瓷材料制作,给压电元件加上交变的电压后,就会产生振动,振动元件在流体中发出声波。利用压电效应发射和接收声波,通过检测流体对超声束(或超声脉冲)的影响来测量流体体积流量。Ultrasonic transducers, made of quartz or ceramic, vibrate when alternating voltages are applied to the piezoelectric elements, which emit sound waves in the fluid. The fluid volume flow is measured by measuring the fluid's effect on the ultrasonic beam (or ultrasonic pulse) by transmitting and receiving sound waves using the piezoelectric effect.

A.
正确
B.
错误
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参考解析:
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【多选题】两个压电元件相串联与单片时相比说法不正确的是( )

A.
串联时输出电压不变,电荷量与单片时相同
B.
串联时输出电压增大一倍,电荷量与单片时相同
C.
串联时电荷量增大一倍,电容量不变
D.
串联时电荷量增大一倍,电容量为单片时的一半