Question

Assertion :In the purely resistive element of a series LCR, AC circuit the maximum value of rms current increases with increase in the angular frequency of the applied emf Reason: $I_{max}=\frac{{\epsilon }_{max}}{z},z=\sqrt{R^2+{(\omega L-\frac{1}{\omega C})}^2}$, Where $I_{max}$ is the peak current in a cylce.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

When the angular frequency of applied emf is less than the resonant frequency$\sqrt{LC}$. Impedance of the circuit decreases so, maximum value of rms current increases with increase in the angular frequency of the applied emf. Thus assertion is correct.

Impedance of circuit is $Z=\sqrt{R^2+(\omega L-1/\omega C{)}^2}$ so maximum value of rms current is $i_m=e_{max}/Z$

Reason is also correct, but not a correct explanation of Assertion.