NTA Abhyas JEE Main2020PhysicsSemiconductorsPractice
In the following circuits, PN-junction diodes D 1 , D 2 and D 3 are ideal for the following potential of A and B , the correct increasing order of resistance between A and B will be ( i ) - 10 V , - 5 V ( ii ) - 5 V , - 10 V ( iii ) - 4 V , - 12 V
Options
- A( i ) < ( ii ) < ( iii )
- B( iii )   <   ( ii )   <   ( i )
- C( ii )   =   ( iii )   <   ( i )
- D( i )   =   ( iii )   <   ( ii )
Correct answer
C. ( ii )   =   ( iii )   <   ( i )
Step-by-step solution
i) In this case of current will flow from B top A. No current will flow through branch C, E (as marked in figure) ⇒    R eq = R 4 + R + R 4 = 3 R 2 ii) Here current will flow from A to B so no current will flow in branch D ⇒    R eq = R 4 + R 2 + R 4 = R iii) Here also current will flow from A to B, so R eq = R same as (ii) ⇒    R ii = R iii  < R i