Question

What is the highest and lowest total resistance that can be secured by combinations of three coils resistances 4 ohms,8ohms,12ohms f

Answer 1

The three resistances are 4 ohms, 8 ohms and 12 ohms

The highest resistance can be offered by these resistors is when they are all connected in series. In series, all the resistances adds up

$R_s = R_1 + R_2 + R_3$

$R_s = 4 + 8 + 12$

$R_s = 24$ Ohms

Hence, the maximum resistance = 24 ohms.

To get the minimum resistance, we need to connect the three resistances in parallel.

Hence, to find the equivalent resistance, we need to use parallel formula

$\frac{1}{R_e_q} = \frac{1}{R_1} +\frac{1}{R_2} +\frac{1}{R_3}$

$\frac{1}{R_e_q} = \frac{1}{4} +\frac{1}{8} +\frac{1}{12}$

$R_e_q = \frac{24}{11}$

$R_e_q = 2.18$ ohms

Hence, the minimum resistance is 2.18 ohms

Answer 2

Answer:

I think, same as the top of the answer