JEE Main20209 Jan 2020Evening ShiftPhysicsCurrent ElectricityActual
In a meter bridge experiment S is a standard resistance. R is a resistance wire. It is found that balancing length is l = 25 c m . If R is replaced by a wire of hall length and half diameter that of R of same material, then the balancing distance l ' (in c m ) will now be ______________.
Correct answer
0
Step-by-step solution
X R = 75 25 = 3 R = p l A = 4 p l π d 2 R ' = 4 p l 2 π d 2 2 = 2 R π d 2 2 then X R ' = 100 - l l 100 - l l = X 2 R = 3 2 l = 40.00   c m