Physics Alternating Current ETEA 2012
PMDC Verified Question 115 of 127
The sinusoidal AC current in a circuit is \(i = 50 \sin (20 t)\). The peak value of current is:
A
100 A
B
25 A
C
50 A
D
20 A
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option C: 50 A
Concept:

The instantaneous alternating current is modeled by the standard sinusoidal equation \(i = I_0 \sin(\omega t)\), where \(I_0\) represents the peak amplitude.

Formula / Reaction:

$$i(t) = I_0 \sin(\omega t)$$

Solution:

  • Comparing \(i = 50 \sin(20t)\) directly with the standard equation \(i = I_0 \sin(\omega t)\):


  • Peak current \(I_0 = 50\text{ A}\).


  • Angular frequency \(\omega = 20\text{ rad/s}\).


Why other options are incorrect:

  • Opt_A: \(100\text{ A}\) represents the peak-to-peak value \(2I_0\), not the peak value.


  • Opt_B: \(25\text{ A}\) is half of the peak current.


  • Opt_D: \(20\text{ rad/s}\) is the angular frequency \(\omega\), not the current amplitude.

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