Alternating currents

Q1. Which statement correctly describes alternating current (AC)?

Multiple Choice · 1 point

• · It flows steadily in one direction
• · Its voltage remains constant
• · It periodically reverses direction
• · It only occurs in mains circuits

Q2. On an oscilloscope, a direct current (DC) signal appears as:

Multiple Choice · 1 point

• · A horizontal straight line
• · A sine wave
• · A vertical line
• · A repeating curve

Q3. Which oscilloscope control adjusts the vertical voltage scale per division?

Multiple Choice · 1 point

• · X-gain
• · Time base
• · Y-gain
• · Trigger level

Q4. If a sinusoidal AC signal has a peak voltage of 120 V, what is the RMS voltage?

Short Answer · 1 point

Q5. A waveform is displayed on an oscilloscope. One cycle spans 5 divisions and the time base is 2 ms/div. What is the frequency?

Short Answer · 1 point

Q6. The RMS voltage of a household AC supply is 230 V. What is the peak voltage?

Multiple Choice · 1 point

• · 230 V
• · 325 V
• · 460 V
• · 115 V

Q7. The peak-to-peak voltage of a sinusoidal AC signal is measured as 200 V. What is the peak voltage?

Multiple Choice · 1 point

• · 100 V
• · 200 V
• · 50 V
• · 400 V

Q8. If the RMS current of an AC circuit is 6 A, what is the peak current?

Short Answer · 1 point

Q9. What does the time period (T) on an oscilloscope trace represent?

Multiple Choice · 1 point

• · Voltage from positive peak to negative peak
• · Duration of one full cycle
• · Maximum current value
• · Average voltage of the waveform

Q10. A sinusoidal AC signal has a peak voltage of 150 V. What is the peak-to-peak voltage?

Short Answer · 1 point

Q11. On an oscilloscope, a waveform spans 8 divisions vertically, and the scale is 5 V/div. What is the peak-to-peak voltage?

Short Answer · 1 point

Q12. Which of the following best defines RMS voltage?

Multiple Choice · 1 point

• · Maximum instantaneous voltage
• · Average of instantaneous voltages
• · DC equivalent voltage that delivers the same power
• · Voltage from peak to peak

Q13. A 50 Hz AC signal has a period of how many milliseconds?

Short Answer · 1 point

Q14. A sinusoidal AC has an RMS voltage of 12 V. What is its peak-to-peak voltage?

Short Answer · 1 point

Q15. Which oscilloscope control is used to measure the frequency of a waveform?

Multiple Choice · 1 point

• · Y-gain
• · Time base
• · Trigger level
• · X-gain

Q16. A sinusoidal AC has a peak current of 5 A. What is the RMS current?

Short Answer · 1 point

Q17. A 60 Hz AC waveform is displayed on an oscilloscope. What is its period?

Short Answer · 1 point