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Karnataka Board PUCPUC Science 2nd PUC Class 12

Determine the equivalent resistance of networks shown in Fig.

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Question

Determine the equivalent resistance of networks shown in Fig.

Numerical
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Solution

It can be observed from the given circuit that in the first small loop, two resistors of resistance 1 Ω each are connected in series.

Hence, their equivalent resistance = (1 + 1) = 2 Ω

It can also be observed that two resistors of resistance 2 Ω each are connected in series.

Hence, their equivalent resistance = (2 + 2) = 4 Ω.

Therefore, the circuit can be redrawn as

It can be observed that 2 Ω and 4 Ω resistors are connected in parallel in all four loops. Hence, equivalent resistance (R’) of each loop is given by,

R' = `(2 xx 4)/(2 + 4)`

= `8/6`

= `4/3` Ω

The circuit reduces to,

All four resistors are connected in series.

Hence, the equivalent resistance of the given circuit is `4/3 xx 4` = `16/3` Ω.

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Chapter 3: Current Electricity - Exercise [Page 129]

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NCERT Physics Part I and II [English] Class 12
Chapter 3 Current Electricity
Exercise | Q 3.20 (c) (a) | Page 129

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