NEET2013PhysicsCurrent ElectricityActual
The resistances of the four arms P, Q, R and S in a Wheatstone's bridge are 10 , 30 , 30 and 90 , respectively. The emf and internal resistance of the cell are 7 ~V and 5 respectively. If the galvanometer resistance is 50 , the current drawn from the cell will be
Options
- A1.0 ~A
- B0.2 ~A
- C0.1 ~A
- D2.0 ~A
Correct answer
B. 0.2 ~A
Step-by-step solution
Effective resistance, R_ eff = 40 120 120+40 = 4800 160 =30 Current = 7 (30+5) = 7 35 =0.2 ~A [ i= E R+r ]