Current Electricity and Electrical InstrumentHard
Question
The effective resistance between points P and Q of the electrical circuit shown in the figure is


Options
A.

B.

C.2r + 4R
D.
+ 2r
+ 2rSolution
The circuit is symmetrical about axis POQ. Therefore the equivalent circuit is drawn

⇒ RPQ =
If a poential difference is applied across P and Q, there will be no currents in arms AO and OB. So these resistance will be ineffective
⇒ RPQ =

If a poential difference is applied across P and Q, there will be no currents in arms AO and OB. So these resistance will be ineffective
Create a free account to view solution
View Solution FreeTopic: Current Electricity and Electrical Instrument·Practice all Current Electricity and Electrical Instrument questions
More Current Electricity and Electrical Instrument Questions
In a potentiometer, a standard cell of 1.1V is balanced through a length of 7.04m For calibration of ammeter the resista...A galvanometer coil has a resistance 90W and full scale deflection correct 10mA. A 910W resistance is connected in serie...A common Emitter circuit is used as a amplifier. Whose current gain is 50. If input resistance is 1KΩ and input vol...Two sources of equal emf are connected to an external resistance R. The internal resistance of the two sources are R1 an...In the circuit shown, the current in the 1Ω resistor is :-...