- #1
songoku
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- Homework Statement
- An alternating current supply is connected in series with a resistor R. The variation with time t (measured in seconds) of the current I (measured in amps) in the resistor is given by the expression I = 9.9 sin(380t). To prevent over-heating, the mean power dissipated in resistor R must not exceed 400 W. Calculate the minimum resistance of R
- Relevant Equations
- mean power = ##I_{rms}^2 \times R##
My calculation: ##400=\left(\frac{9.9}{\sqrt{2}}\right)^2 R## and I got R = 8.2 ohm
But the answer key used Io (9.9 A) instead of Irms
Why?
Thanks
But the answer key used Io (9.9 A) instead of Irms
Why?
Thanks