Capacitors

JEE Main level, single correct, medium

19 of 180

Question 19 of 180

This question has Statement 1 and Statement 2 . Of the four choices given after the Statements, choose the one that best describes the two Statements.
Statement 1: It is not possible to make a sphere of capacity 1 farad using a conducting material.
Statement 2: It is possible for earth as its radius is 6.4×106 m6.4 \times 10^6 \mathrm{~m}.

Show answer and solution

Answer: (D) Statement 1 is true, Statement 2 is false.

Capacitance of sphere is given by:
C=4πϵ0rC=4 \pi \epsilon_0 r
If, C=1 FC=1 \mathrm{~F} then radius of sphere needed:
r=C4πϵ0=14π×8.85×10−12r=\frac{C}{4 \pi \epsilon_0}=\frac{1}{4 \pi \times 8.85 \times 10^{-12}}
or, r=10124π×8.85=9×109 mr=\frac{10^{12}}{4 \pi \times 8.85}=9 \times 10^9 \mathrm{~m}
9×109 m9 \times 10^9 \mathrm{~m} is very large, it is not possible to obtain such a large sphere. Infact earth has radius 6.4×106 m6.4 \times 10^6 \mathrm{~m} only and capacitance of earth is 711μF711 \mu \mathrm{F}.

JEE Main question paper PDF

Open a shift to read the full paper on this page, or download it.

JEE Main 2025 Apr 2 Shift 1 question paper

Open Download PDF

Opening paper…

Explain it as a whiteboard videoStep-by-step, in Hinglish or English. Your first video needs no login.Solved it on paper but got it wrong?Upload a photo of your working. Mistake Doctor marks the exact line that broke.
See it move: Capacitors, dielectrics and RC circuits simulationDrag the sliders and watch the numbers in this question change.

More Physics practice

JEE Main Physics practice question on Capacitors (Capacitance), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.