Question

Find the unknown resistance in the figure shown, to the nearest hundredth of an ohm, if the total (equivalent) resistance is 0.28

Please help asap!

Answer 1

The unknown resistance is approximately 0.44 Ω.

Solution:

Total (equivalent) resistance = 0.28 Ω

Resistance 1 = ?

Resistance 2 = 0.81 Ω

To find the unknown resistance.

Formula for determining equivalent resistance in a parallel circuit:

`$(1)/(R_(e q))=(1)/(R_(1))+(1)/(R_(2))`

Substitute the given values in the formula.

`$(1)/(0.28)=(1)/(R_(1))+(1)/(0.81)`

`$3.571=(1)/(R_(1))+1.235`

Subtract 1.235 on both sides of the equation, we get

`$2.282=(1)/(R_(1))`

Take reciprocal to find
`R_1`.

`$R_(1)=(1)/(2.282)`

`$R_(1)=0.44`

`R_1` = 0.44 Ω

The unknown resistance is approximately 0.44 Ω.