Electronics-Alternating Current vs Direct Current
Electronics-Alternating Current vs Direct Current
1. What are the two main applications for ac?
- direct, pulsating
- electric, magnetic
- power, information
- static, dynamic
2. The distance that a signal's energy can travel in the time it takes for one cycle to occur is called the signal's:
- amplitude
- frequency
- wavelength
- period
3. One oscilloscope selector knob that allows the major and minor divisions of the graticule to be used to determine a signal amplitude value is called the:
- time/cm control
- position control
- intensity control
- volts/cm control
4. If current varies periodically from zero to a maximum, back to zero, and then repeats, the signal is:
- direct
- alternating
- pulsating
- repetitive
6. What is the peak value of a household appliance that uses a 230 V ac source?
- 163 V
- 230 V
- 325 V
- 480 V
7. What is the waveform period difference between the 60 Hz electricity used in this country and the 50 Hz used in Europe?
- 3 ms
- 16 ms
- 4 ms
- 20 ms
8. Test equipment selection enables the technician to both generate signals and:
- change circuit conditions
- inject signals
- sense circuit conditions
- change signal frequencies
9. Why is ac current transfer more effective than dc current transfer over long distances?
- due to the height of power lines
- due to the use of ac generators
- due to step-up and step-down transformers reducing I2R losses
- due to very high voltages
10. Which percentages of full-amplitude rise time are used for a pulse wave?
- 0 to 50 percent
- 0 to 100 percent
- 5 to 95 percent
- 10 to 90 percent