JEE Mains · Physics · STD 12 - Electric charges and fields
- JEE Mains 2019
- Hard
- MCQ
For a uniformly charged ring of radius \(R\), the electric field on its axis has the largest magnitude at a distance \(h\) from its centre. Then value of \(h\) is
Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \(\frac{R}{{\sqrt 2 }}\)
Step-by-step Solution
Detailed explanation
Electric field \(E=\frac{k Q x}{\left(x^{2}+R^{2}\right)^{3 / 2}}\)
For maxima \(\frac{d E}{d x}=0\)
After solving we get, \(\left(x \pm \frac{\mathrm{R}}{\sqrt{2}}\right)\)
More questions from Physics
- In an experiment with a convex lens. The plot of the image distance (\(v'\)) against the object distance \(\left(\mu^{\prime}\right)\) measured from the focus gives a curve \(v^{\prime} \mu^{\prime}=225\). If all the distances are measured in \(cm\). The magnitude of the focal length of the lens is \(cm\).JEE Mains 2022 Medium
- Two masses \(M _{1}\) and \(M _{2}\) are tied together at the two ends of a light inextensible string that passes over a frictionless pulley. When the mass \(M _{2}\) is twice that of \(M_{1}\). the acceleration of the system is \(a_{1}\). When the mass \(M_{2}\) is thrice that of \(M_{1}\). The acceleration of The system is \(a_{2}\). The ratio \(\frac{a_{1}}{a_{2}}\) will be.
JEE Mains 2022 Medium - The height in terms of radius of the earth \((R)\), at which the acceleration due to gravity becomes \(\dfrac{g}{9}\), where \(g\) is acceleration due to gravity on earth's surface, is ______.JEE Mains 2026 Medium
- A small cube of side \(1\) mm is placed at the centre of a circular loop of radius \(10\) cm carrying a current of \(2\) A. The magnetic energy stored inside the cube is \(\alpha \times 10^{-14}\) J. The value of \(\alpha\) is _______. (\(\mu_o = 4\pi \times 10^{-7}\) Tm/A, \(\pi = 3.14\))JEE Mains 2026 Hard
- Name the logic gate equivalent to the diagram attached
JEE Mains 2023 Medium - 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 \(1\) : Very large size telescopes are reflecting telescopes instead of refracting telescopes. Statement \(2\) : It is easier to provide mechanical support to large size mirrors than large size lenses.JEE Mains 2013 Hard
More PYQs from JEE Mains
- Light is incident from a medium into air at two possible angles of incidence \((A)\, 20^o\) and \((B)\, 40^o\) . In the medium light travels \(3.0\, cm\) in \(0.2\, ns\). The ray willJEE Mains 2013 Hard
- A galvanometer coil has \(500\) turns and each turn has an average area of \(3 \times 10^{-4}\, m ^{2}\). If a torque of \(1.5\,Nm\) is required to keep this coil parallel to magnetic field when a current of \(0.5\, A\) is flowing through it, the strength of the field (in \(T )\) isJEE Mains 2020 Medium
- A small particle moves to position \(5 \hat{i}-2 \hat{j}+\hat{k}\) from its initial position \(2 \hat{i}+3 \hat{j}-4 \hat{k}\) under the action of force \(5 \hat{i}+2 \hat{j}+7 \hat{k} N\). The value of work done will be \(............J\).JEE Mains 2023 Easy
- Two conductors have the same resistances at \(0^{\circ} \mathrm{C}\) but their temperature coefficients of resistance are \(\alpha_1\) and \(\alpha_2\). The respective temperature coefficients for their series and parallel combinations are _______.JEE Mains 2024 Hard
- Given below are two statements: Statement \(I :\) In a diatomic molecule, the rotational energy at a given temperature obeys Maxwell's distribution. Statement \(II :\) In a diatomic molecule, the rotational energy at a given temperature equals the translational kinetic energy for each molecule. In the light of the above statements, choose the correct answer from the options given below:JEE Mains 2021 Medium
- A conducting circular loop made of a thin wire, has area \(3.5 \times 10^{-3}\, m^2\) and resistance \(10\,\Omega \). It is placed perpendicular to a time dependent magnetic field \(B(t) = (0.4\,T)\, sin\, (50\, \pi t)\). The field is uniform in space. Then the net charge flowing through the loop during \(t = 0\, s\) and \(t = 10\, ms\) is close to.......\(mC\)JEE Mains 2019 Hard