IIT JEE , AIEEE Forum - Physics , Electricity

chetan_kp

when u are asked to calculate equivalent resisatnce or other similar question.........how do u identify the points of equal potential...........for ex in the given example how to identify pts. of equal potential......

vrtual

C ,I & G AT EQUIPOTENTIAL FOR THEY HAVE EQUAL NO. OF RESISTANCE ON BOTH THE SIDES.

THEY ARE SYMMETRIC POINTS

THEY WILL HAVE HALF THE POTENTIAL APPLIED ACROSS AE

chetan_kp

but according to the answer B and H are also at same potential.............why....plz explain in detail........

tarinbansal

Yes,vrtual's answer is correct.

And dude, obviously B and H are also at same potential becoz they are directly connected to terminal A and have equal resistance in between, so A's potential wud be equally shared by the 2 points.

But these equipotential points dont help in solving the circuit.
C,I,G are equipotential becoz they cut the circuit symmetrically in 2 halves.
Another way to identify equipotential points is that they must be at equal distance from both terminals and U must encounter same resistances if U travel from both terminals to those points.(try applying this concept on C,I,G. U will understand).

chetan_kp

please find the equivalent resistance for the above arrangement with ur expln..........

chetan_kp

pls reply

tarinbansal

I am getting 3r/2 as the equivalent resistance of this circuit.

chetan_kp

ans is right but could u please explain about points of equal potential in this case and hence find the equivalent resistance...........

tarinbansal

See, C,G,I are at the same potential. And we know that potential remains same in a conductor. So imagine that C,G,I are connected with a conducting wire. Connect them with a wire(means cut the circuit in 2 halves). And solve half the circuit(its really easy to solve half of this circuit). And the 2 halves wud be is series, so just do the double of equivalent resistance of half circuit.

Hope U get it.

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