Suppose you possess three resistors of 20 , 50 and 100 . What minimum and maximum resistances can be obtained from these resistors?

Question

Quantrex Academy · Accepted Answer

Correct answer: D. 12.5 , 170

To obtain the maximum resistance, all the resistors must be connected in series.

R_\max = R_1 + R_2 + R_3

R_\max = 20 + 50 + 100 = 170 \Omega

To obtain the minimum resistance, all the resistors must be connected in parallel.

\dfrac{1}{R_\min} = \dfrac{1}{R_1} + \dfrac{1}{R_2} + \dfrac{1}{R_3}

\dfrac{1}{R_\min} = \dfrac{1}{20} + \dfrac{1}{50} + \dfrac{1}{100}

\dfrac{1}{R_\min} = \dfrac{5 + 2 + 1}{100} = \dfrac{8}{100}

R_\min = \dfrac{100}{8} = 12.5 \Omega

The minimum and maximum resistances are

12.5 \Omega

and

170 \Omega

respectively.

Suppose you possess three resistors of 20 , 50 and 100 . What...