Question

Given the resistances of 1Ω , 2Ω ,3Ω (one each), which of the following effective
resistance values cannot be obtained by using all of them?
A)$\frac{11}{3}$
B)$\frac{11}{4}$
C)$\frac{11}{5}$
D)$\frac{11}{7}$

Answer 1

Answer:

1 + 2+3= 11/4 that the matter

Answer 2

Correct Question:-

Given the resistances of 1Ω , 2Ω ,3Ω (one each), which of the following effective

resistance values can be obtained by using all of them?

A)$\frac{11}{3}$

B)$\frac{11}{4}$

C)$\frac{11}{5}$

D)$\frac{11}{7}$

Answer

• R1=1ohm
• R2=2ohm
• R3=3ohm

Option-1

Correct R1 and R2 in parallel

$\\ \sf\longmapsto \dfrac{1}{R_{12}}=\dfrac{1}{1}+\dfrac{1}{2}$

$\\ \sf\longmapsto\dfrac{1}{R_{12}}=\dfrac{2+1}{2}$

$\\ \sf\longmapsto \dfrac{1}{R_{12}}=\dfrac{3}{2}$

$\\ \sf\longmapsto R_{12}=\dfrac{2}{3}\Omega$

• Connect with R3

$\\ \sf\longmapsto R_{123}=\dfrac{2}{3}+3$

$\\ \sf\longmapsto R_{123}=\dfrac{2+9}{3}$

$\\ \sf\longmapsto R_{123}=\dfrac{11}{3}$

Hence it can be possible.