JEE Mains · Physics · STD 12 - 2. Electric potential and capacitance
The electric potential at the centre of two concentric half rings of radii \(R_1\) and \(R_2\), having same linear charge density \(\lambda\) is
- A \(\frac{2 \lambda}{\epsilon_0}\)
- B \(\frac{\lambda}{2 \epsilon_0}\)
- C \(\frac{\lambda}{4 \epsilon_0}\)
- D \(\frac{\lambda}{\epsilon_0}\)
Answer & Solution
Correct Answer
(B) \(\frac{\lambda}{2 \epsilon_0}\)
Step-by-step Solution
Detailed explanation
Potential at centre \(V=\frac{\left(\lambda \cdot \pi R_2\right)}{4 \pi \varepsilon_0 R_2}+\frac{\left(\lambda \cdot \pi R_1\right)}{4 \pi \varepsilon_0 R_1}\) \(=\frac{\lambda}{2 \varepsilon_0}\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- For a body projected at an angle with the horizontal from the ground, choose the correct statement.JEE Mains 2023 Medium
- A massless spring \((k = 800\, N/m)\), attached with a mass \((500\, g)\) is completely immersed in \(1\, kg\) of water. The spring is stretched by \(2\, cm\) and released so that it starts vibrating. What would be the order of magnitude of the change in the temperature of water when the vibrations stop completely? (Assume that the water container and spring receive negligible heat and specific heat of mass \(= 400\, J/kg\, K\), specific heat of water \(= 4184\, J/kg\, K\))JEE Mains 2019 Hard
- A sample of an ideal gas is taken through the cyclic process \(abca\) as shown in the figure. The change in the internal energy of the gas along the path \(ca\) is \(-180\, J\). The gas absorbs \(250\, J\) of heat along the path \(ab\) and \(60\, J\) along the path \(bc\). The work done by the gas along the path \(abc\) is ..... \(J\)
JEE Mains 2019 Medium - An artillery piece of mass \(M_1\) fires a shell of mass \(\mathrm{M}_2\) horizontally. Instantaneously after the firing, the ratio of kinetic energy of the artillery and that of the shell is _______.JEE Mains 2024 Hard
- The electrostatic force \(\left(\vec{F}_1\right)\) and magnetic force \(\left(\vec{F}_2\right)\) acting on a charge \(q\) moving with velocity \(v\) can be written _______.JEE Mains 2024 Hard
- A photon of wavelength \(\lambda \) is scattered from an electron, which was at rest. The wavelength shift \(\Delta \lambda \) is three times of \( \lambda \) and the angle of scattering \(\theta \) is \(60^o\) . The angle at which the electron recoiled is \(\phi \). The value of \(tan\,\phi \) is : ( electron speed is much smaller than the speed of light)JEE Mains 2014 Hard
More PYQs from JEE Mains
- \(\sum_{\substack{i, j=0 \\ i \neq j}}^{n}{ }^{n} C_{i}{ }^{n} C_{j}\) is equal toJEE Mains 2022 Hard
- In a physical balance working on the principle of moments, when \(5\, mg\) weight is placed on the left pan, the beam becomes horizontal. Both the empty pans of the balance are of equal mass. Which of the following statements is correct?JEE Mains 2017 Medium
- Match List-I with List-II.
List-I (Physical Quantity) List-II (Dimensional Formula) (A) Coefficient of viscosity (I) [ML0T-3] (B) Intensity of wave (II) [ML-2T-2] (C) Pressure gradient (III) [M-1LT2] (D) Compressibility (IV) [ML-1T-1]
Choose the correct answer from the options given below :JEE Mains 2025 Medium - A particle starts from origin \(O\) from rest and moves with a uniform acceleration along the positive \(x -\) axis. Identify all figures that correctly represent the motion qualitatively. (\(a =\) acceleration, \(v =\) velocity, \(x =\) displacement, \(t =\) time)
JEE Mains 2019 Hard - Current measured by the ammeter \((A)\) in the reported circuit when no current flows through \(10\,\Omega\) resistance. will be________\(A\)
JEE Mains 2022 Hard - A block of mass \(2\,kg\) moving on a horizontal surface with speed of \(4\,ms ^{-1}\) enters a rough surface ranging from \(x =0.5\,m\) to \(x =1.5\,m\). The retarding force in this range of rough surface is related to distance by \(F =- kx\) where \(k =12\,Nm ^{-1}\). The speed of the block as it just crosses the rough surface will be ........... \(\,ms ^{-1}\)JEE Mains 2022 Hard