Physics Circle home Student Login

Home›Chapters›Capacitors PYQs›Dielectrics›Question 57

JEE Main 2023 (6 Apr, Shift 1) · Dielectrics

Dielectrics question from JEE Main 2023 (6 Apr, Shift 1)

Q57JEE Main 2023 · 6 APR · SHIFT 1Medium

Dielectrics

A parallel plate capacitor with plate area AA and plate separation dd is filled with a dielectric material of dielectric constant K=4K = 4. The thickness of the dielectric material is xx, where x<dx < d.

Figure

Let C1C_1 and C2C_2 be the capacitance of the system for x=13dx = \frac{1}{3}d and x=2d3x = \frac{2d}{3}, respectively. If C1=2μFC_1 = 2\mu\text{F} the value of C2C_2 is __________ μF\mu\text{F}

Numerical answer type. Work it out, then open the answer.

Show answer and solution

Answer: 3

  1. C=ϵ0Ad−x+x4=ϵ0Ad−3x4C=\frac{\epsilon_0A}{d-x+\frac{x}{4}}=\frac{\epsilon_0A}{d-\frac{3x}{4}}
  2. x=d3x=\frac{d}{3}: gap term =3d4=\frac{3d}{4}; x=2d3x=\frac{2d}{3}: gap term =d2=\frac{d}{2}
  3. C2C1=3/41/2=1.5\frac{C_2}{C_1}=\frac{3/4}{1/2}=1.5
  4. C2=1.5×2=3 μFC_2=1.5\times2=3\ \mu\text{F}
Report a mistake

More questions on Dielectrics