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