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The power of a certain CD player operating at 120 V rms is 20.0 W. Assuming that the CD player behaves like a pure resistance, find

(a) the maximum instantaneous power (40 W)
(b) the rms current.
(c) the resistance of this player.

Respuesta :

Answer:

(a) Maximum instantaneous power P = 40 watt

(b) Rms current will be 0.166 A

(C) Resistance will be 720 ohm

Explanation:

We have given CD player is operating power V = 120 volt and P = 20 watt

First we calculate the (c) part so that we can we use the value of resistance

(c) We know that power is given by

[tex]P=\frac{V_{rms}^2}{R}[/tex]

[tex]20=\frac{120^2}{R}[/tex]

[tex]R=720\Omega[/tex]

(B) Rms current is given by

Current [tex]i=\frac{V_{RMS}}{R}=\frac{120}{720}=0.166[/tex]

(B) Now maximum instantaneous power is given by

[tex]P=I_0^2R[/tex]

[tex]i_0=\sqrt{2}i_{rms}=1.414\times 0.166=0.2356A[/tex]

So power [tex]P=0.2356^2\times 720=40watt[/tex]

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