Question

A series AC circuit has a resistance of 4 Ω and a reactance of 3 Ω. The impedance of the circuit is
(a) 5 Ω
(b) 7 Ω
(c) 12/7 Ω
(d) 7/12 Ω

Answer 1

A series AC circuit has a resistance of 4 Ω and a reactance of 3 Ω. The impedance of the circuit is Option (a) 5 Ω

Therefore the correct answer is Option (a)

Explanation:

The circuit impedance is given by the

$z=\sqrt{R^{2}+X^{2}}$

where

Impedance is expressed in ohms, and may include resistance (R), inductive (XL), and capacitive (XC) reactance.

Given data in the question  

R=4 Ω  

X=3 Ω  

Put the given values of resistance R and reactance X in above equation  

We get  $z=\sqrt{4^{2}+3^{2}}$

$Z=\sqrt{16+9}$

$z=\sqrt{25}$

Square root of twenty five is five  

So that

=5 Ω