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Question
Calculate the combined resistance in each case:
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Solution
case 1
Let the total resistance of the combination shown in the diagram below be R.
Here 500 Ω and 1000 Ω resistors are connected in series combination. Their net resistance is given by R = R1+ R2
Here:
R1=500 Ω
R2=1000 Ω
So:
R = 500 + 1000 = 1500 Ω
Thus, the total resistance of the combination is 1500 Ω.
case 2
In the circuit diagram shown above, two 2 Ω resistors are connected in parallel combination.
Therefore:
`1/R_-p=1/R_1+1/R_2`
`1/R_p=1/2+1/2`
`Ω1/R_p=2/2=1`Ω
Thus the total resistance of the combination is 1 Ω.
case 3
In the circuit diagram shown above, two 4 Ω resistors are connected in parallel combination.
Therefore their resulant resistance given by
`1/R=1/R1+1/R_2`
`Here R_1=4`Ω
`R_2=4`Ω
So
`1/R=1/4+1/4`
`or 1/R=2/4`
or R=2Ω
In the above circuit diagram, this 2 Ω and 3 Ω resistors are connected in series combination. So, the total resistance of the circuit can be calculated as:
`R=R_1+R_2`
Here
`R_1=2`â
`R_2=3`â
So:
R=2â+3â=5â
Thus, the total resistance of the combination is 5 â„
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