Most Important Selected Qs for JEE AdvancedPhysicsCurrent Electricity
In the circuit shown in figure A B is a uniform wire of length L=5 ~m . It has a resistance of 2 / m . When A C=2.0 ~m , it was found that the galvanometer shows zero reading when switch s is placed in either of the two positions 1 or 2. Find the emf E ₁ . (mark the answer in V )
Correct answer
150
Step-by-step solution
aligned & V_ A C =E_ 3 = 3 0 V & V_ C B =E_ 2 & E_ 2 3 0 = V_ C B V_ A C & E_ 2 3 0 = 3 2 [ V_ C B V_ A C = I_ C B I_ A C = 3 2 ] & E_ 2 = 4 5 V & V_ A B = 3 0 + 4 5 = 7 5 V & R_ A B = 2 5 = 1 0 aligned Current through A B is 7 5 1 0 = 7 . 5 A aligned & E₁= 7 . 5 (R_ A B +R ) & = 1 5 0 V . aligned