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JAMB Physics 1997 Question 47

Question 47

Alternating Current Circuits

The voltage of the domestic electric supply is represented by the equation V = 311 sin 314.2t. Determine the frequency of the a.c. supply. [π = 3.142]

  1. A.50.0 Hz
  2. B.100.0 Hz
  3. C.311.0 Hz
  4. D.314.2 Hz
Show the answer and explanation

Answer: A (50.0 Hz)

Explanation

Compare with V = V0 sin 2πft: 2πf = 314.2, so f = 314.2 ÷ 6.284 = 50.0 Hz.