# Two resistors are in the ratio 1:4. If these are connected in parallel there total resistance becomes 20 ohm. Find the value of each resistance.

## Answers

**Answer:**

let the resistance be 1x and 4x

answer is 25 ohm and 100 ohm

**Explanation:**

1/R = 1/R1 +1/R2

1/20= 1/x +1/4x

1/20 = 5x/4x²

1/20 = 5/4x

4x/5= 20

x= 100/4

x = 25

so the two resistors

x and 4x

25 ohm and 100 ohm

**Answer:**

The 1st Resistor, R1 = x = 25 Ω

The 2nd Resistor, R2 = 4x = 4 × 25 = 100 Ω

**Explanation:**

Given,

Two resistors are in the ratio = 1:4

Let the first resistors be **x****.**

Let the second resistors be **4****x****.**

**By**** ****using**** the**** formula**** of**** ****parallel combination of resistors****.**

1/Rp =1/R1 + 1/R2

**.****°****.**** ****Rp**** ****=**** ****R1**** ****×**** ****R2**** ****/**** ****R1**** ****+**** ****R2**

**Putt****ing**** the**** ****values**

=> 20 = x × 4x **/**** **x + 4x

=> 20 = 4x² **/**** **5x

=> 20 = 4x × x **/**** **5 × x

'x' is canceled.

=> 20 = 4x **/**** **5

=> 20 × 5 = 4x

=> 100 = 4x

=> 4x = 100

=> x = 100 **/**** **4

**.****°****.**** ****x**** ****=**** ****2****5**

Now, putting the values of** ****x**** **to get the resistance of resistors.

So,

The 1st Resistor, R1 = x = 25 Ω

The 2nd Resistor, R2 = 4x = 4 × 25 = 100 Ω