Question

eq resistance if 2 resistors of 90 ohm and 30 ohm are connected in parrallel circuit​

Answer 1

Answer:

The equivalent resistance is 22.5 Ω

Explanation:

Given :

Two resistors of 90 Ω and 30 Ω are connected in parallel.

To find :

the equivalent resistance

Solution :

When resistors of resistances R₁ , R₂ , R₃ .... are connected in parallel, the equivalent resistance (R) is given by

      1/R = 1/R₁ + 1/R₂ + 1/R₃ + ...

Put

• R₁ = 90 Ω
• R₂ = 30 Ω

The equivalent resistance is given by,

  $\sf \dfrac{1}{R}=\dfrac{1}{R_1}+\dfrac{1}{R_2} \\\\ \sf R=\dfrac{R_1 R_2}{R_1 +R_2}$

Substitute,

$\sf R=\dfrac{90 \times 30}{90+30} \\\\ \sf R=\dfrac{2700}{120} \\\\ \sf R=\dfrac{270}{12} \\\\ \sf R=\dfrac{6 \times 45}{6 \times 2} \\\\ \sf R=\dfrac{45}{2} \\\\ \sf R=22.5 \ \Omega$

Therefore, the equivalent resistance is 22.5 Ω