Question

2.18
The electrical resistance between points A and B
of the fig. 13.43 shown is,
222
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202
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222
А
B
(A) (2/3)2
(C) (3/2) 22
(Β) 2 Ω
(D) 6 Ω​

Answer 1

Answer:

In this case, the 3 resistors of 1Ω on the upper half of the circuit are connected in series and the combined resistance R

1

is given as 1+1+1=3Ω .

The 3 resistors of 2 ohms on the lower half of the circuit are connected in series and the combined resistance R

2

is given as 2+2+2=6Ω.

The resistances R

1

, R

2

and 2Ω in the middle are connected in parallel. So the combined resistance R3 of this parallel connection is given as

3

1

+

2

1

+

6

1

=

1

1

=1ohm. That is, the resistance in the closed loop is reduced to 1 ohm.

Now the total resistance R across the circuit is given as R

1

+R

2

+R

3

=1+1+1=3Ω.

Hence, the value of the resistance in the circuit from A to B is 3Ω.