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), 50Hz AC supply, the series inductor needed for it to work is close to:

• A. 0.88 H
• B. 0.44 H
• C. 0.065 H
• D. 80 H

Answer 1

The correct option is C

0.065 H

$R=\frac{V}{I}=8\Omega$

P = 800 W

$(220{)}^2=(10\times 8{)}^2+(314\times L\times 10{)}^2$

$\Rightarrow L=0.065H$