MHT CET20249 May 2024Morning ShiftPhysicsCurrent ElectricityActual
When the two known resistance ' R ' and ' S ' are connected in the left and right gaps of a meter bridge respectively, the null point is found at a distance ' l₁ ' from the zero end of a meter bridge wire. An unknown resistance ' X ' is now connected in parallel with ' S ' and null point is found at a distance ' l₂ ' form zero end of meter bridge wire. The unknown resistance ' X ' is
Options
- AS l₁ (100-l₂ ) 100 (l₂-l₁ )
- BS l₂ (100-l₁ ) 100 (l₁-l₂ )
- C100 (l₂-l₁ ) Sl ₁ (100-l₂ )
- D100 (l₂-l₁ ) S l₂ (100-l₁ )
Correct answer
A. S l₁ (100-l₂ ) 100 (l₂-l₁ )
Step-by-step solution
As per the first condition, R l₁ = S 100-l₁ As per the second condition, array ll & R l₂ = XS ( X + S ) (100-l₂ ) & l_ S ~S 100-l₁ = l₂ XS ( X + S ) (100-l₂ ) & 100-l₁ l₁ = (1+ S X ) 100-l₂ l₂ & 1+ S X = l₂ (100-l₁ ) l₁ (100-l₂ ) & S X = l₂ (100-l₁ )-l₁ (100-l₂ ) l₁ (100-l₂ ) = 100 (l₂-l₁ ) l₁ (100-l₂ ) & X = Sl ₁ (100-l₂ ) 100 (l₂-l₁ ) array