Engineering Board Exam Reviewer · Alternating Current and Voltage · easy
The sinusoidal voltage shown is plotted against time in milliseconds. Find its frequency.
- 50 Hz
- 100 Hz
- 25 Hz
- 314 Hz
Answer
A. 50 Hz
Solution
One complete cycle takes T=20 ms (the wave repeats after 20 ms). f=1/T= 120 ms=50 Hz.
More Alternating Current and Voltage questions
- Two currents i1=10 t A and i2=10 ( t+120°) A flow into a junction and add. What is the peak value of the total current?
- How long does it take a 400 Hz sine voltage, starting at zero, to reach 70.7% of its peak value for the first time?
- A sinusoidal voltage has an rms value of 120 V. At what angle in the first quadrant of the cycle does its instantaneous value equal 100 V?
- The rectangular pulse train shown has a period of 10 ms and is at 20 V for the first 4 ms of each period and zero for the rest. Find its…
- The voltage shown is a sine wave riding on a dc level (it swings between -10 V and +30 V). Find its rms value.
- Two series-connected sources produce v1=30 t V and v2=40 ( t+90°) V. What is the peak value of the total voltage?
- A sinusoidal voltage with a peak value of 100 V is applied across a 50, resistor. What average power does the resistor dissipate?
- How long does a 60 Hz sine wave take to go from zero to 45° of its cycle?
- Given v=100 ( t+20°) V and i=8 ( t-40°) A, which statement is correct?
- A voltage is given by v=311 (377t) V. What is its frequency?