Biology Forums - Study Force

In an AC series circuit the capacitive reactance is 253 W and frequency is 100 Hz. What is the capacitance?
 a. 6.29 mF
  c. 50.0 mF
  b. 8.0 mF
  d. 3.2 mF

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[Ques. 2] A 1.5-m string is held fixed at both ends. When driven by a 180-Hz source, the string vibrates in 3 distinct segments. What is the natural fundamental frequency of the string?
 a. 30 Hz
  c. 90 Hz
  b. 60 Hz
  d. 540 Hz

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[Ques. 3] The frequency in an AC series circuit is halved. By what factor does this change the capacitive reactance?
 a. 1/2
  c. 1/4
  b. 4
  d. 2

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[Ques. 4] A standing wave is set up in a 100-cm string fixed at both ends. The string vibrates in 5 distinct segments when driven by a 120-Hz source. What is the wavelength?
 a. 10 cm
  c. 40 cm
  b. 20 cm
  d. 80 cm

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[Ques. 5] In the typical household AC voltage of 120 V, what is the peak voltage?
 a. 170 V
  c. 85 V
  b. 240 V
  d. 120 V

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[Ques. 6] A 100-m long high-voltage cable is suspended between two towers. The mass of the 100-m cable is 200 kg. If the tension in the cable is 20,000 N, what is the lowest frequency at which this cable can oscillate?
 a. 0.50 Hz
  c. 0.75 Hz
  b. 0.61 Hz
  d. 1.5 Hz

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[Ques. 7] The peak voltage of an AC source is 400 V. What is the rms voltage?
 a. 100 V
  c. 141 V
  b. 200 V
  d. 283 V

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[Ques. 8] If a guitar string has a fundamental frequency of 250 Hz, what is the frequency of its third harmonic?
 a. 250 Hz
  c. 1000 Hz
  b. 750 Hz
  d. 1500 Hz

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[Ques. 9] An AC voltage source, with a peak output of 120 V, results in dissipation of energy in a resistor at rate of 50.0 W. What is the value of the resistance?
 a. 100 W
  c. 144 W
  b. 120 W
  d. 72.0 W

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[Ques. 10] The lowest A on a piano has a frequency of 27.5 Hz. If the tension in the 2.0-m long string is 151 N and one-half wavelength occupies the string, what is the mass of the string?
 a. 100 g
  c. 37 g
  b. 25 g
  d. 50 g

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