Question

An inductor coil and a capacitor and a resistance of $5 \, \Omega$ are connected in series to an a.c. source of rms voltage $30 \, V$ . When the frequency of the source is varied, a maximum r.m.s. current of $5 \, A$ is observed. If this inductor is connected in parallel with a resistance $5 \, \Omega$ to a battery of emf $25 \, V$ and internal resistance $2.0 \, \Omega$ , the current drawn from the battery is

• A. $\frac{1 5 0}{1 7}A$
• B. $2.5A$
• C. $\frac{1 2 5}{3 3}A$
• D. $\frac{1 2 5}{9 9}A$

Answer 1

Answer: (A)

Let resistance of inductor be $\mu $
$\text{I}_{\text{max}}=\frac{3 0}{5 + \mu }=5\Rightarrow \mu =1\Omega$

Now, $\text{I} = \frac{2 5}{\frac{5}{6} + 2}$

$=\frac{1 5 0}{1 7}\text{A}$