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In the network shown in the Fig, each resistance is 1Ω. The effective resistance between A and B is
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- 4/3 Ω
- 3/2 Ω
- 7 Ω
- 8/7 Ω
Correct Option: D
At A current is distributed and at B currents are collected. Between A and B, the distribution is symmetrical. It has been shown in the figure. It appears that current in AO and OB remains same. At O, current i4 returns back without any change. If we detach O from AB there will not be any change in distribution. Now, CO & OD will be in series hence its total resistance = 2Ω
| It is in parallel with CD, so, equivalent resistance = | = | Ω | ||
| 2 + 1 | 3 |
This equivalent resistance is in series with AC & DB, so, total resistance
| = | + 1 + = | Ω | ||
| 3 | 3 |
Now 8/3 Ω is parallel to AB, that is, 2Ω, so total resistance
| ABCD = 1 + | + 1 = | Ω | ||
| 3 | 3 |
