Download App

Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsElectrostatic Potential and Capacitance2 Marks
Question
A cylindrical capacitor is constructed using two coaxial cylinders of the same length 10cm and of radii 2mm and 4mm:
  1. Calculate the capacitance.
  2. Another capacitor of the same length is constructed with cylinders of radii 4mm and 8mm. Calculate the capacitance.
✓

Answer

  1. $\text{C}=\frac{2\in_0\text{L}}{\text{ln}\big(\frac{\text{R}_2}{\text{R}_1}\big)}=\frac{\text{e}\times3.14\times8.85\times10^{-2}\times10^{-1}}{\text{ln}2}$ $[\text{ln 2}=0.6932]$
$=80.17\times10^{-13}$

$\Rightarrow8\text{PF}$
  1. Same as $\frac{\text{R}_2}{\text{R}_1}$ will be same.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "2 Marks Questions" from Electrostatic Potential and Capacitance→Electrostatic Potential and Capacitance — all question types→Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Two beams, one of red light and the other of blue light, of the same intensity are incident on a metallic surface to emit photoelectrons. Which one of the two beams emits electrons of greater kinetic energy?
→
Find the moment of inertia of a pair of spheres, each having a mass m and radius r, kept in contact about the tangent passing through the point of contact.
→
In a Van de Graaff type generator a spherical metal shell is to be a $15 \times 10^6 \mathrm{~V}$ electrode. The dielectric strength of the gas surrounding the electrode is $5 \times 10^7 \mathrm{Vm}^{-1}$. What is the minimum radius of the spherical shell required? (You will learn from this exercise why one cannot build an electrostatic generator using a very small shell which requires a small charge to acquire a high potential.)
→
For a given light sensitive material and a source of incident radiation of fixed frequency, how does the photoelectric current decay with the intensity of incident light?
→
Define equipotential surface.
→
Name the logic gate which can be realised by using a p-n junction diode in the given diagram. Give its logic symbol and write the truth table. Name the gate which will be obtained by combining with a NOT gate.
→
A boy is standing on a platform which is free to rotate about its axis. The boy holds an open umbrella in his hand. The axis of the umbrella coincides with that of the platform. The moment of inertia of "the platform plus the boy system" is $3.0 \times 10^{-3} \mathrm{~kg}-\mathrm{m}^2$ and that of the umbrella is $2.0 \times 10^3 \mathrm{~kg}-\mathrm{m}^2$. The boy starts spinning the umbrella about the axis at an angular speed of $2.0 \mathrm{rev} / \mathrm{s}$ with respect to himself. Find the angular velocity imparted to the platform.
→
Give some commonly known ideas regarding magnetism.
→
Distinguish between diamagnetic and ferromagnetic materials in terms of
i. susceptibility and
ii. their behaviour in a non-uniform magnetic field
→
Define resolving power of a compound microscope. How does the resolving power of a compound microscope change when.
  1. refractive index of the medium between the object and objective lens increases?
  2. wavelength of the radiation used is increased?
→