Question

How will you connect three resistors of 2 Ω, 3 Ω and 5 Ω respectively so as to obtain a resultant of 2.5 Ω? Draw the diagram to show the arrangement.

Answer 1

To get the resistance of 2.5 Ώ, we will have to connect the resistors of values 2 Ώ and 3 Ώ in series and this arrangement should be connected in parallel with the resistor of value 5 Ώ. 

  

 Resistance 2 Ω and 3 Ω are in series their net resistance is `R=R_1+R_2`

^R=2Ω+3Ω 

^R=5Ω 

^{This 5 Ω resistance is in parallel with another 5 Ω resistance therefore their net resistance is:'} 

^{`1/R=1/R_1+1/R_1`} 

^{`1/R=1/5+1/5`}

^1/R=2/5 

^{R=2.5Ω Hence, net resistance of the combination will be 2.5 Ω}