Electro Magnetic Induction And Alternating Currents Question 202
Question: An arc lamp requires a direct current of 10 A at 80 V to function. If it is connected to a 220 V (rms),50 Hz AC supply, the series inductor needed for it to work is close to :
Options:
A) 0.044 H
B) 0.065 H
C) 80 H
D) 0.08 H
Show Answer
Answer:
Correct Answer: B
Solution:
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Here $ i,=\frac{e}{\sqrt{R^{2}+X_{L}^{2}}}=\frac{e}{\sqrt{R^{2}+{{\omega }^{2}}L^{2}}}=\frac{e}{\sqrt{R^{2}+4{{\pi }^{2}}v^{2},L^{2}}} $
$ 10,=\frac{220}{\sqrt{64+4{{\pi }^{2}},{{(50)}^{2}},L}} $
$ [ \because R=\frac{V}{I}=\frac{80}{10}=8 ] $ On solving we get L = 0.065 H
