COMEDK · Physics · 17. Electrostatics
Two identieal metal spheres charged with \(+12 \mu \mathrm{F}\) and \(-8 \mu \mathrm{F}\) are kept at certain distance in air. They are brought into contact and then kept at the same distance. The ratio of the magnitudes of electrostatic forces between them before and after contact is
- A \(12: 1\)
- B \(8: 1\)
- C \(24: 1 .\)
- D \(4: 1\)
Answer & Solution
Correct Answer
(C) \(24: 1 .\)
Step-by-step Solution
Detailed explanation
\[ \begin{aligned} Q_{1} &=12 \mu \mathrm{F}=12 \times 10^{-6} \mathrm{~F} \\ Q_{2} &=-8 \mu \mathrm{F} \\ &=-8 \times 10^{-6} \mathrm{~F} \end{aligned} \] Initial value of electrostatic force of attraction between both spheres,…
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
- A car is moving in a circular horizontal track of radius \(10 \mathrm{~m}\) with a constant speed of \(10 \mathrm{~m} / \mathrm{s}\). A bob is suspended from the roof of the car by a light wire of length \(1.0 \mathrm{~m}\). The angle made by the wire with the vertical isCOMEDK 2013 Medium
- Two spring of force constant \(k_{1}\) and \(k_{2}\) are configured as the figure given below
The angular frequency of this configuration isCOMEDK 2021 Easy - The displacement of a wave is given by \(y=20 \cos (\omega t+4 z)\). The amplitude of the given wave isCOMEDK 2021 Medium
- The mass number of two nuclei \(\mathrm{P}\) and \(\mathrm{Q}\) are 27 and 125 respectively. The ratio of their radii \(R_P: R_Q\) is given by:COMEDK 2023 Easy
- A metallic rod of length '\(a\)' is rotated with an angular frequency of \(0.2 \mathrm{~rads}^{-1}\) about an axis normal to the rod passing through its one end. A constant and uniform magnetic field of '\(\mathrm{B}\)' T parallel to the axis exists everywhere. The emf developed across the ends of the rod isCOMEDK 2024 Easy
- When a certain metal surface is illuminated with light of frequency \(\nu\), the stopping potential for photoelectric current is \(V_0\). When the same surface is illuminated by light of frequency \(\dfrac{\nu}{2}\), the stopping potential is \(\dfrac{V_0}{4}\). The threshold frequency for photoelectric emission isCOMEDK 2023 Medium
More PYQs from COMEDK
- \(\int_{-8}^{8}\left(\sin ^{93} x+x^{295}\right) d x=\)COMEDK 2012 Medium
- Consider the reaction
\(\mathrm{Fe}_2 \mathrm{O}_3(\mathrm{~s})+3 \mathrm{CO}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{Fe}(\mathrm{l})+3 \mathrm{CQ}_2(\mathrm{~g})\)
In accordance with Le-Chatlier's principle, which of the following will not disturbs the equilibrium?COMEDK 2025 Easy - Which of the product is not possible in Wurtz reaction?COMEDK 2022 Easy
- A crane with a steel cable of length \(11 \mathrm{~m}\) and radius \(2.0 \mathrm{~cm}\) is employed to lift a block of concrete of mass 40 tons in a building site. If the Young's modulus of steel is \(2.0 \times 10^{11} \mathrm{~Pa}\), what will be roughly the increase in the length of the cable while lifting the block?
(Take, \(g=10 \mathrm{~ms}^{-2}\) )COMEDK 2015 Medium - If \(I_{1}=\int_{0}^{\pi / 2} x \sin x d x\) and \(I_{2}=\int_{0}^{\pi / 2} x \cos x d x\), then which one of the following is true?COMEDK 2016 Easy
- If \(A\) is the angle of prism, \(r\) angle of refraction, then the condition for minimum deviation isCOMEDK 2014 Easy