A.40HZ
B.50HZ
C.60HZ
D.70HZ
[单选题]超声诊断仪典型的脉冲重复频率为A.10HzB.50HzC.100HzD.1000HzE.1MHz
[单选题]超声的声波频率应大于A.2000HzB.20000HzC.50000HzD.5000HzE.10000Hz
[单选题]人耳可听到声波频率应小于A.2000HzB.20000HzC.50000HzD.5000HzE.10000Hz
[单选题]调制中频电流的调制波的频率通常是A.l~10HzB.l~50HzC.1~100HzD.1~150HzE.10~200Hz
[单选题]计算机电源的频率范围是()HZ。A . 20B . 30C . 40D . 50
[单选题]如果对70Hz节律的脑波以70Hz的采样频率进行采样,形成脑波的形态是( )。A.与原始脑波形态相同B.呈一条直线C.仅是单个采样点,不能形成波形D
[单选题]计算机电源的输入电压频率是()Hz.A . 20B . 30C . 40D . 50
[单选题]梳状波的频率分布为( )。A.2~5HzB.5~7HzC.9~13HzD.13~17HzE.5~7Hz及13~17Hz
[单选题]干扰电疗法差频为A.0~1000HzB.0~100HzC.50~200HzD.0~50HzE.100~200Hz
[单选题]干扰电疗法其差频为A.0~1000HzB.0~100HzC.50~200HzD.0~50HzE.100~200Hz