NEET2025PhysicsCapacitanceActual
The plates of a parallel plate capacitor are separated by d. Two slabs of different dielectric constant K₁ and K₂ with thickness 3 8 d and d 2 , respectively are inserted in the capacitor. Due to this, the capacitance becomes two times larger than when there is nothing between the plates. (If K₁=1.25 K₂ , the value of K₁ is:
Options
- A2.66
- B2.33
- C1.60
- D1.33
Correct answer
A. 2.66
Step-by-step solution
C₁= ₀ A / d aligned & C ₂= ₀ ~A 3 ~d 8 ~K ₁ + d 2 ~K ₂ + ( d - 3 ~d 8 - d 2 ) & C ₂= ₀ ~A / d 3 8 ~K ₁ + 1 2 ~K ₂ + 1 8 & = ₀ ~A / d 3 8 ~K ₁ + 1 2 ( 4 5 ~K ₁ ) + 1 8 & C ₂=2 C ₁ & ₀ ~A / d 3 8 ~K ₁ + 5 8 ~K ₁ + 1 8 =2 ₀ ~A / d & 1 1 ~K ₁ + 1 8 =2 1 ~K ₁ + 1 8 = 1 2 ~K ₁= 8 3 =2.66 aligned