A) 50 Hz
B) 60 Hz
C) 80 Hz
D) 100 Hz
Correct Answer: C
Solution :
[c] With dc: \[P=\frac{{{V}^{2}}}{R}\Rightarrow R=\frac{{{(10)}^{2}}}{20}=5\Omega ;\] With ac: \[P=\frac{V_{rms}^{2}R}{{{Z}^{2}}}\Rightarrow {{Z}^{2}}=\frac{{{(10)}^{2}}\times 5}{10}=50\,{{\Omega }^{2}}\] Also \[{{Z}^{2}}={{R}^{2}}+4{{\pi }^{2}}{{V}^{2}}{{L}^{2}}\] \[\Rightarrow 50={{(5)}^{2}}+4{{(3.14)}^{2}}{{V}^{2}}{{(10\times {{10}^{-3}})}^{2}}\Rightarrow v=80Hz\]You need to login to perform this action.
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