Question

Resistors R1, R2, and R3 are connected in parallel. R1 is 68 ohm and R2 is 93 ohm. The equivalent resistance of the parallel combination is 26-ohm. What is the resistance of R3?
please show work! :)

Answer 1

Answer:

77 Ω

Explanation:

For resistors in parallel:

1/R = 1/R₁ + 1/R₂ + 1/R₃

1/26 = 1/68 + 1/93 + 1/R₃

1/R₃ = 0.013

R₃ = 77

The resistance of R₃ is 77 Ω.

Answer 2

Answer:

R3=76.9 ohm

Explanation:

Hello

the  equivalent resistance is given by the expression:

$\frac{1}{R_{eq} } =\frac{1}{R_{1} } +\frac{1}{R_{2} }+\frac{1}{R_{3} }+...\frac{1}{R_{n} }$

we have R1=68 ohm, R=93 ohm, Rt=26 and the resistor R3 is unknown.

$\frac{1}{26 } =\frac{1}{68 } +\frac{1}{93} }+\frac{1}{R_{3} }\\\frac{1}{26 } =\frac{((93*R_{3})+(68*R_{3})+(68*93)) }{68*93*R_{3} }\\26((93*R_{3})+(68*R_{3})+(68*93)) }={68*93*R_{3} }\\\\\\2418R_{3}+1768R_{3}+164424=6324R_{3}\\R_{3}(2418+1768-6324)=164424\\-2138R_{3}=-164424\\R_{3}=\frac{164424}{2138}\\ R_{3}=76.9 ohm$

Have a great day.