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The voltage E and the current I in an in...

The voltage E and the current I in an instrument are represented by the equations:
`E=2cos omegatV`
`I=2sin omegat A`
The average power dissipated in the instrument will be

A

zero

B

1.0 W

C

4 W

D

2.0 W

Text Solution

AI Generated Solution

The correct Answer is:
To find the average power dissipated in the instrument given the voltage and current equations, we can follow these steps: ### Step-by-Step Solution: 1. **Identify the given equations**: - Voltage: \( E = 2 \cos(\omega t) \) volts - Current: \( I = 2 \sin(\omega t) \) amperes 2. **Determine the peak values**: - The peak voltage \( V_0 \) is 2 volts. - The peak current \( I_0 \) is 2 amperes. 3. **Calculate RMS values**: - The RMS (Root Mean Square) voltage \( V_{RMS} \) is given by: \[ V_{RMS} = \frac{V_0}{\sqrt{2}} = \frac{2}{\sqrt{2}} = \sqrt{2} \text{ volts} \] - The RMS current \( I_{RMS} \) is given by: \[ I_{RMS} = \frac{I_0}{\sqrt{2}} = \frac{2}{\sqrt{2}} = \sqrt{2} \text{ amperes} \] 4. **Determine the phase difference**: - The voltage is represented by a cosine function and the current by a sine function. The phase difference \( \phi \) between them is: \[ \phi = \frac{\pi}{2} \text{ radians} \quad (\text{or } 90^\circ) \] 5. **Use the formula for average power**: - The average power \( P \) is calculated using the formula: \[ P = V_{RMS} \cdot I_{RMS} \cdot \cos(\phi) \] 6. **Substitute the values**: - Substituting the RMS values and the cosine of the phase difference: \[ P = (\sqrt{2}) \cdot (\sqrt{2}) \cdot \cos\left(\frac{\pi}{2}\right) \] - Since \( \cos\left(\frac{\pi}{2}\right) = 0 \): \[ P = (\sqrt{2}) \cdot (\sqrt{2}) \cdot 0 = 0 \text{ watts} \] ### Conclusion: The average power dissipated in the instrument is \( 0 \) watts.
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