Question

Four resistors are connected in series such that their total resistance is 50ohm . If the resistance of resistors is 5 ohm , 10ohm and 15 ohm respectively .find tue resistance of the fourth resistor

Answer 1

Answer:

$\boxed{R_{4}=20\Omega}$

Step-by-step explanation:

If resistors are in series, so the current  $I$ is the same in all of them. In this problem we have four resistors. So, we can get a relationship between the Equivalent resistance  of series combination and the four resistors as follows:

$R_{eq}=R_{1}+R_{2}+R_{3}+R_{4}$

$R_{eq}$ is the total resistance $50\Omega$. Moreover:

$R_{1}=5\Omega \\ R_{2}=10\Omega \\ R_{3}=15\Omega$

Therefore:

$50=5+10+15+R_{4} \\ \\ R_{4}=50-(5+10+15) \\ \\ R_{4}=50-30 \\ \\ \boxed{R_{4}=20\Omega}$