Question

Given below are two statements:
Statement I : An AC circuit undergoes electrical resonance if it contains either a capacitor or an inductor. 
Statement II : An AC circuit containing a pure capacitor or a pure inductor consumes high power due to its non-zero power factor.
In the light of above statements, choose the correct answer from the options given below :

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Answer 1

The Correct Option is B

Statement I: An AC circuit undergoes electrical resonance only when both a capacitor and an inductor are present in the circuit, as their reactances cancel each other out. Therefore, the statement that resonance can occur with just a capacitor or an inductor is false. 

Statement II: A pure capacitor or a pure inductor in an AC circuit does not consume real power because they do not have a power factor that is non-zero. In the case of a pure capacitor or inductor, the power factor is zero, and the average power consumed is also zero. 

Thus, the statement about high power consumption due to a non-zero power factor is false. For resonance, both capacitor and inductor are required to ensure the circuit reaches resonance, where the phase difference \( \phi = 0 \) and the reactances cancel out.