Question

A $24\Omega$ resistor, an inductor with a reactance of $120\Omega$, and a capacitor with a reactance of $120\Omega$ are in series across a $60V$ source. The circuit is at resonance. The voltage across the inductor is

• A. $60V$
  
• B. $660V$
  
• C. $30V$
  
• D. $300V$
  

Answer 1

The correct option is D $300V$

Resistance=$R=24\Omega$

Reactance of coil$=X_L=120\Omega$

Reactance of capacitor$=X_C=120\Omega$

Impedance of circuit$=X=\sqrt{R^2+(X_C-X_L{)}^2}$

$⟹X=\sqrt{{24}^2+(120-120{)}^2}=24\Omega$

Current$=I=\frac{E}{X}=\frac{60}{24}=2.5A$

Voltage across the inductor=$V_L=I{X}_L=2.5\times 120$

$⟹V_L=300V$

Answer-(D)