Question

A series $AC$ circuit has a resistance of $4\Omega$ and a reactance of $3\Omega$. The impedance of the circuit is

• A. $5\Omega$
• B. $7\Omega$
• C. $12/7\Omega$
• D. $7/12\Omega$

Answer 1

The correct option is A $5\Omega$

$Impedance\left(Z\right)=\sqrt{R^2+X^2}$

where, $R=resistance$

$X=reactance$
Given $R=4\Omega$ and $X=3\Omega$
Substitute values back in equation

$Z=\sqrt{4^2+3^2}$

$Z=5\Omega$